diff --git a/core/chain_makers.go b/core/chain_makers.go
index 5a8f380a36..584d2faa7f 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -185,11 +185,15 @@ func GenerateChain(parent *types.Block, db ethdb.Database, n int, gen func(int,
 			panic(fmt.Sprintf("state write error: %v", err))
 		}
 		h.Root = root
+		for _, receipt := range b.receipts {
+			fmt.Printf("%+v\n", receipt)
+		}
 		return types.NewBlock(h, b.txs, b.uncles, b.receipts), b.receipts
 	}
 	for i := 0; i < n; i++ {
 		header := makeHeader(parent, statedb)
 		block, receipt := genblock(i, header)
+		fmt.Printf("%x\n\n", block.Header().ReceiptHash)
 		blocks[i] = block
 		receipts[i] = receipt
 		parent = block
diff --git a/core/index_test.go b/core/index_test.go
new file mode 100644
index 0000000000..9837f97b99
--- /dev/null
+++ b/core/index_test.go
@@ -0,0 +1,160 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package core
+
+import (
+	"bytes"
+	"fmt"
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+// blackHoleContract is a trivial Ethereum contract that can just store some data
+// points in its state trie. It's goal is to have a means to test functionality
+// depending on evolving state roots.
+//
+// contract BlackHole {
+//     mapping (int256 => uint) public data;
+//
+//     function set(int256 key, uint value) {
+//         data[key] = value;
+//     }
+// }
+var blackHoleContract = common.Hex2Bytes("6060604052605f8060106000396000f3606060405260e060020a60003504639398e0cd81146024578063a22c554014603b575b005b605560043560006020819052908152604090205481565b600435600090815260208190526040902060243590556022565b6060908152602090f3")
+var blackHoleSetter = common.Hex2Bytes("a22c5540")
+
+// Tests that state trie indexes are properly constructed for an entire chain of
+// imported blocks, cross referencing between various state roots, as well as
+// making sure that state updates do not lose reference entries.
+func TestChainIndex(t *testing.T) {
+	// Configure the test chain and ensure we have enough funds to play with
+	var (
+		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+		key2, _ = crypto.HexToECDSA("8a1f9a8f95be41cd7ccb6168179afb4504aefe388d1e14474d32c45c72ce7b7a")
+		key3, _ = crypto.HexToECDSA("49a7b37aa6f6645917e7b807e9d1c00d4fa71f18343b0d4122a4d2df64dd6fee")
+		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
+		addr2   = crypto.PubkeyToAddress(key2.PublicKey)
+		addr3   = crypto.PubkeyToAddress(key3.PublicKey)
+		db, _   = ethdb.NewMemDatabase()
+	)
+	genesis := WriteGenesisBlockForTesting(db, GenesisAccount{addr1, big.NewInt(10000000000)})
+
+	// Generate a chain will all kinds of events happening in it
+	var contract common.Address
+
+	chain, _ := GenerateChain(genesis, db, 8, func(i int, gen *BlockGen) {
+		switch i {
+		case 0:
+			// In block 1, addr1 sends addr2 some ether.
+			tx, _ := types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(10000), params.TxGas, nil, nil).SignECDSA(key1)
+			gen.AddTx(tx)
+		case 1:
+			// In block 2, addr1 sends some more ether to addr2.
+			// addr2 passes it on to addr3.
+			tx1, _ := types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(key1)
+			tx2, _ := types.NewTransaction(gen.TxNonce(addr2), addr3, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(key2)
+			gen.AddTx(tx1)
+			gen.AddTx(tx2)
+		case 2:
+			// Block 3 is empty but was mined by addr3.
+			gen.SetCoinbase(addr3)
+			gen.SetExtra([]byte("yeehaw"))
+		case 3:
+			// Block 4 includes blocks 2 and 3 as uncle headers (with modified extra data).
+			b2 := gen.PrevBlock(1).Header()
+			b2.Extra = []byte("foo")
+			gen.AddUncle(b2)
+			b3 := gen.PrevBlock(2).Header()
+			b3.Extra = []byte("foo")
+			gen.AddUncle(b3)
+		case 4:
+			// In block 5, we create a simple storage contract to add data entries to
+			tx, _ := types.NewContractCreation(gen.TxNonce(addr1), big.NewInt(31415), params.GenesisGasLimit, big.NewInt(1), blackHoleContract).SignECDSA(key1)
+			contract = crypto.CreateAddress(addr1, tx.Nonce())
+			gen.AddTx(tx)
+		case 5:
+			// In block 6, we store a single entry into the storage to check single update indexing
+			key := common.Hex2BytesFixed("01", 32)
+			val := common.Hex2BytesFixed("02", 32)
+
+			tx, _ := types.NewTransaction(gen.TxNonce(addr1), contract, nil, params.GenesisGasLimit, nil, append(append(blackHoleSetter, key...), val...)).SignECDSA(key1)
+			gen.AddTx(tx)
+		case 6:
+			// In block 7, we store a lot of entries into the storage to check multi update indexing
+			for i := int64(0); i < 50; i++ {
+				key := common.Hex2BytesFixed(common.Bytes2Hex(big.NewInt(i).Bytes()), 32)
+				val := common.Hex2BytesFixed(common.Bytes2Hex(big.NewInt(i+2).Bytes()), 32)
+
+				tx, _ := types.NewTransaction(gen.TxNonce(addr1), contract, nil, big.NewInt(45000), nil, append(append(blackHoleSetter, key...), val...)).SignECDSA(key1)
+				gen.AddTx(tx)
+			}
+		}
+	})
+	// Import the chain. This runs all block validation rules.
+	evmux := &event.TypeMux{}
+
+	vm.Debug = true
+
+	blockchain, _ := NewBlockChain(db, FakePow{}, evmux)
+	if i, err := blockchain.InsertChain(chain); err != nil {
+		t.Fatalf("block %d: insert failed: %v\n", i, err)
+		return
+	}
+	// Iterate over all the blocks and check the state trie indexes
+	indexes := make(map[string]struct{})
+
+	for block := uint64(0); block <= blockchain.CurrentBlock().NumberU64(); block++ {
+		// Gather all the indexes that should be present in the database
+		root := blockchain.GetBlockByNumber(block).Root()
+
+		stateDb, err := state.New(root, db)
+		if err != nil {
+			t.Fatalf("failed to create state trie at %x: %v", root, err)
+		}
+		fmt.Println(blockchain.GetBlockByNumber(block).Transactions())
+		for it := state.NewNodeIterator(stateDb); it.Next(); {
+			if (it.Hash != common.Hash{}) && (it.Parent != common.Hash{}) {
+				fmt.Printf("%d: %x -> %x\n", block, it.Parent, it.Hash)
+				indexes[string(trie.ParentReferenceIndexKey(it.Parent.Bytes(), it.Hash.Bytes()))] = struct{}{}
+			}
+		}
+	}
+	// Cross check the indexes and the database itself
+	fmt.Println(len(indexes))
+	for index, _ := range indexes {
+		if _, err := db.Get([]byte(index)); err != nil {
+			t.Errorf("failed to retrieve reported index %x: %v", index, err)
+		}
+	}
+	for _, key := range db.Keys() {
+		if bytes.HasPrefix(key, trie.ParentReferenceIndexPrefix) {
+			if _, ok := indexes[string(key)]; !ok {
+				t.Errorf("index entry not reported %x", key)
+			}
+		}
+	}
+}
diff --git a/core/state/state_object.go b/core/state/state_object.go
index 47546112f4..292f32f301 100644
--- a/core/state/state_object.go
+++ b/core/state/state_object.go
@@ -118,7 +118,7 @@ func (c *StateObject) setAddr(addr []byte, value common.Hash) {
 		// if RLPing failed we better panic and not fail silently. This would be considered a consensus issue
 		panic(err)
 	}
-	c.trie.Update(addr, v)
+	c.trie.UpdateIndexed(addr, v, nil)
 }
 
 func (self *StateObject) Storage() Storage {
diff --git a/core/types/derive_sha.go b/core/types/derive_sha.go
index 00c42c5bc6..68d803e448 100644
--- a/core/types/derive_sha.go
+++ b/core/types/derive_sha.go
@@ -35,7 +35,7 @@ func DeriveSha(list DerivableList) common.Hash {
 	for i := 0; i < list.Len(); i++ {
 		keybuf.Reset()
 		rlp.Encode(keybuf, uint(i))
-		trie.Update(keybuf.Bytes(), list.GetRlp(i))
+		trie.UpdateIndexed(keybuf.Bytes(), list.GetRlp(i), nil)
 	}
 	return trie.Hash()
 }
diff --git a/core/vm/contract.go b/core/vm/contract.go
index 95417e7471..5981dcca0d 100644
--- a/core/vm/contract.go
+++ b/core/vm/contract.go
@@ -27,6 +27,7 @@ type ContractRef interface {
 	ReturnGas(*big.Int, *big.Int)
 	Address() common.Address
 	SetCode([]byte)
+	EachStorage(cb func(key, value []byte))
 }
 
 // Contract represents an ethereum contract in the state database. It contains
@@ -124,3 +125,9 @@ func (self *Contract) SetCallCode(addr *common.Address, code []byte) {
 	self.Code = code
 	self.CodeAddr = addr
 }
+
+// EachStorage iterates the contract's storage and calls a method for every key
+// value pair.
+func (self *Contract) EachStorage(cb func(key, value []byte)) {
+	self.caller.EachStorage(cb)
+}
diff --git a/core/vm/environment.go b/core/vm/environment.go
index 299d126747..4fee583bfb 100644
--- a/core/vm/environment.go
+++ b/core/vm/environment.go
@@ -121,4 +121,5 @@ type Account interface {
 	Address() common.Address
 	ReturnGas(*big.Int, *big.Int)
 	SetCode([]byte)
+	EachStorage(cb func(key, value []byte))
 }
diff --git a/core/vm/jit_test.go b/core/vm/jit_test.go
index aa97e51844..8c50ed0f5c 100644
--- a/core/vm/jit_test.go
+++ b/core/vm/jit_test.go
@@ -125,14 +125,15 @@ type vmBench struct {
 
 type account struct{}
 
-func (account) SubBalance(amount *big.Int)   {}
-func (account) AddBalance(amount *big.Int)   {}
-func (account) SetBalance(*big.Int)          {}
-func (account) SetNonce(uint64)              {}
-func (account) Balance() *big.Int            { return nil }
-func (account) Address() common.Address      { return common.Address{} }
-func (account) ReturnGas(*big.Int, *big.Int) {}
-func (account) SetCode([]byte)               {}
+func (account) SubBalance(amount *big.Int)             {}
+func (account) AddBalance(amount *big.Int)             {}
+func (account) SetBalance(*big.Int)                    {}
+func (account) SetNonce(uint64)                        {}
+func (account) Balance() *big.Int                      { return nil }
+func (account) Address() common.Address                { return common.Address{} }
+func (account) ReturnGas(*big.Int, *big.Int)           {}
+func (account) SetCode([]byte)                         {}
+func (account) EachStorage(cb func(key, value []byte)) {}
 
 func runVmBench(test vmBench, b *testing.B) {
 	var sender account
diff --git a/core/vm/vm.go b/core/vm/vm.go
index 4b03e55f04..8e07aaa899 100644
--- a/core/vm/vm.go
+++ b/core/vm/vm.go
@@ -376,12 +376,9 @@ func (self *Vm) log(pc uint64, op OpCode, gas, cost *big.Int, memory *Memory, st
 			stck[i] = new(big.Int).Set(item)
 		}
 		storage := make(map[common.Hash][]byte)
-		/*
-			object := contract.self.(*state.StateObject)
-			object.EachStorage(func(k, v []byte) {
-				storage[common.BytesToHash(k)] = v
-			})
-		*/
+		contract.self.EachStorage(func(k, v []byte) {
+			storage[common.BytesToHash(k)] = v
+		})
 		self.env.AddStructLog(StructLog{pc, op, new(big.Int).Set(gas), cost, mem, stck, storage, err})
 	}
 }
diff --git a/trie/iterator_test.go b/trie/iterator_test.go
index 815743bfdc..43ee56963d 100644
--- a/trie/iterator_test.go
+++ b/trie/iterator_test.go
@@ -37,7 +37,7 @@ func TestIterator(t *testing.T) {
 	v := make(map[string]bool)
 	for _, val := range vals {
 		v[val.k] = false
-		trie.Update([]byte(val.k), []byte(val.v))
+		trie.UpdateIndexed([]byte(val.k), []byte(val.v), nil)
 	}
 	trie.Commit()
 
diff --git a/trie/proof_test.go b/trie/proof_test.go
index 6b5bef05c4..0530dff357 100644
--- a/trie/proof_test.go
+++ b/trie/proof_test.go
@@ -119,14 +119,14 @@ func randomTrie(n int) (*Trie, map[string]*kv) {
 	for i := byte(0); i < 100; i++ {
 		value := &kv{common.LeftPadBytes([]byte{i}, 32), []byte{i}, false}
 		value2 := &kv{common.LeftPadBytes([]byte{i + 10}, 32), []byte{i}, false}
-		trie.Update(value.k, value.v)
-		trie.Update(value2.k, value2.v)
+		trie.UpdateIndexed(value.k, value.v, nil)
+		trie.UpdateIndexed(value2.k, value2.v, nil)
 		vals[string(value.k)] = value
 		vals[string(value2.k)] = value2
 	}
 	for i := 0; i < n; i++ {
 		value := &kv{randBytes(32), randBytes(20), false}
-		trie.Update(value.k, value.v)
+		trie.UpdateIndexed(value.k, value.v, nil)
 		vals[string(value.k)] = value
 	}
 	return trie, vals
diff --git a/trie/secure_trie.go b/trie/secure_trie.go
index fb5f694d8e..aabffb40f7 100644
--- a/trie/secure_trie.go
+++ b/trie/secure_trie.go
@@ -79,36 +79,6 @@ func (t *SecureTrie) TryGet(key []byte) ([]byte, error) {
 	return t.Trie.TryGet(t.hashKey(key))
 }
 
-// Update associates key with value in the trie. Subsequent calls to
-// Get will return value. If value has length zero, any existing value
-// is deleted from the trie and calls to Get will return nil.
-//
-// The value bytes must not be modified by the caller while they are
-// stored in the trie.
-func (t *SecureTrie) Update(key, value []byte) {
-	if err := t.TryUpdate(key, value); err != nil && glog.V(logger.Error) {
-		glog.Errorf("Unhandled trie error: %v", err)
-	}
-}
-
-// TryUpdate associates key with value in the trie. Subsequent calls to
-// Get will return value. If value has length zero, any existing value
-// is deleted from the trie and calls to Get will return nil.
-//
-// The value bytes must not be modified by the caller while they are
-// stored in the trie.
-//
-// If a node was not found in the database, a MissingNodeError is returned.
-func (t *SecureTrie) TryUpdate(key, value []byte) error {
-	hk := t.hashKey(key)
-	err := t.Trie.TryUpdate(hk, value)
-	if err != nil {
-		return err
-	}
-	t.Trie.db.Put(t.secKey(hk), key)
-	return nil
-}
-
 // UpdateIndexed is an extended version of Update, where state trie index entries
 // are also generated for all entities referencing the current node.
 //
diff --git a/trie/secure_trie_test.go b/trie/secure_trie_test.go
index 13c6cd02e9..59ee267efc 100644
--- a/trie/secure_trie_test.go
+++ b/trie/secure_trie_test.go
@@ -45,7 +45,7 @@ func TestSecureDelete(t *testing.T) {
 	}
 	for _, val := range vals {
 		if val.v != "" {
-			trie.Update([]byte(val.k), []byte(val.v))
+			trie.UpdateIndexed([]byte(val.k), []byte(val.v), nil)
 		} else {
 			trie.Delete([]byte(val.k))
 		}
@@ -59,7 +59,7 @@ func TestSecureDelete(t *testing.T) {
 
 func TestSecureGetKey(t *testing.T) {
 	trie := newEmptySecure()
-	trie.Update([]byte("foo"), []byte("bar"))
+	trie.UpdateIndexed([]byte("foo"), []byte("bar"), nil)
 
 	key := []byte("foo")
 	value := []byte("bar")
diff --git a/trie/sync_test.go b/trie/sync_test.go
index 6738427bfb..f1c67b5e6d 100644
--- a/trie/sync_test.go
+++ b/trie/sync_test.go
@@ -37,17 +37,17 @@ func makeTestTrie() (ethdb.Database, *Trie, map[string][]byte) {
 		// Map the same data under multiple keys
 		key, val := common.LeftPadBytes([]byte{1, i}, 32), []byte{i}
 		content[string(key)] = val
-		trie.Update(key, val)
+		trie.UpdateIndexed(key, val, nil)
 
 		key, val = common.LeftPadBytes([]byte{2, i}, 32), []byte{i}
 		content[string(key)] = val
-		trie.Update(key, val)
+		trie.UpdateIndexed(key, val, nil)
 
 		// Add some other data to inflate th trie
 		for j := byte(3); j < 13; j++ {
 			key, val = common.LeftPadBytes([]byte{j, i}, 32), []byte{j, i}
 			content[string(key)] = val
-			trie.Update(key, val)
+			trie.UpdateIndexed(key, val, nil)
 		}
 	}
 	trie.Commit()
diff --git a/trie/trie.go b/trie/trie.go
index 88b32aa45a..93dc48a55e 100644
--- a/trie/trie.go
+++ b/trie/trie.go
@@ -146,30 +146,6 @@ func (t *Trie) TryGet(key []byte) ([]byte, error) {
 	return tn.(valueNode).Value, nil
 }
 
-// Update associates key with value in the trie. Subsequent calls to
-// Get will return value. If value has length zero, any existing value
-// is deleted from the trie and calls to Get will return nil.
-//
-// The value bytes must not be modified by the caller while they are
-// stored in the trie.
-func (t *Trie) Update(key, value []byte) {
-	if err := t.TryUpdate(key, value); err != nil && glog.V(logger.Error) {
-		glog.Errorf("Unhandled trie error: %v", err)
-	}
-}
-
-// TryUpdate associates key with value in the trie. Subsequent calls to
-// Get will return value. If value has length zero, any existing value
-// is deleted from the trie and calls to Get will return nil.
-//
-// The value bytes must not be modified by the caller while they are
-// stored in the trie.
-//
-// If a node was not found in the database, a MissingNodeError is returned.
-func (t *Trie) TryUpdate(key, value []byte) error {
-	return t.tryUpdateIndexed(key, value, nil)
-}
-
 // UpdateIndexed is an extended version of Update, where state trie index entries
 // are also generated for all entities referencing the current node.
 //
diff --git a/trie/trie_test.go b/trie/trie_test.go
index 35d043cdf1..fffb6c6315 100644
--- a/trie/trie_test.go
+++ b/trie/trie_test.go
@@ -54,7 +54,7 @@ func TestNull(t *testing.T) {
 	var trie Trie
 	key := make([]byte, 32)
 	value := common.FromHex("0x823140710bf13990e4500136726d8b55")
-	trie.Update(key, value)
+	trie.UpdateIndexed(key, value, nil)
 	value = trie.Get(key)
 }
 
@@ -97,7 +97,7 @@ func TestMissingNode(t *testing.T) {
 	}
 
 	trie, _ = New(root, db)
-	err = trie.TryUpdate([]byte("120099"), []byte("zxcvzxcvzxcvzxcvzxcvzxcvzxcvzxcv"))
+	err = trie.TryUpdateIndexed([]byte("120099"), []byte("zxcvzxcvzxcvzxcvzxcvzxcvzxcvzxcv"), nil)
 	if err != nil {
 		t.Errorf("Unexpected error: %v", err)
 	}
@@ -130,7 +130,7 @@ func TestMissingNode(t *testing.T) {
 	}
 
 	trie, _ = New(root, db)
-	err = trie.TryUpdate([]byte("120099"), []byte("zxcv"))
+	err = trie.TryUpdateIndexed([]byte("120099"), []byte("zxcv"), nil)
 	if _, ok := err.(*MissingNodeError); !ok {
 		t.Errorf("Wrong error: %v", err)
 	}
@@ -304,7 +304,7 @@ func paranoiaCheck(t1 *Trie) (bool, *Trie) {
 	t2 := new(Trie)
 	it := NewIterator(t1)
 	for it.Next() {
-		t2.Update(it.Key, it.Value)
+		t2.UpdateIndexed(it.Key, it.Value, nil)
 	}
 	return t2.Hash() == t1.Hash(), t2
 }
@@ -356,8 +356,8 @@ func TestOutput(t *testing.T) {
 
 func TestLargeValue(t *testing.T) {
 	trie := newEmpty()
-	trie.Update([]byte("key1"), []byte{99, 99, 99, 99})
-	trie.Update([]byte("key2"), bytes.Repeat([]byte{1}, 32))
+	trie.UpdateIndexed([]byte("key1"), []byte{99, 99, 99, 99}, nil)
+	trie.UpdateIndexed([]byte("key2"), bytes.Repeat([]byte{1}, 32), nil)
 	trie.Hash()
 
 }
@@ -374,8 +374,8 @@ func TestLargeData(t *testing.T) {
 	for i := byte(0); i < 255; i++ {
 		value := &kv{common.LeftPadBytes([]byte{i}, 32), []byte{i}, false}
 		value2 := &kv{common.LeftPadBytes([]byte{10, i}, 32), []byte{i}, false}
-		trie.Update(value.k, value.v)
-		trie.Update(value2.k, value2.v)
+		trie.UpdateIndexed(value.k, value.v, nil)
+		trie.UpdateIndexed(value2.k, value2.v, nil)
 		vals[string(value.k)] = value
 		vals[string(value2.k)] = value2
 	}
@@ -419,7 +419,7 @@ func benchGet(b *testing.B, commit bool) {
 	k := make([]byte, 32)
 	for i := 0; i < benchElemCount; i++ {
 		binary.LittleEndian.PutUint64(k, uint64(i))
-		trie.Update(k, k)
+		trie.UpdateIndexed(k, k, nil)
 	}
 	binary.LittleEndian.PutUint64(k, benchElemCount/2)
 	if commit {
@@ -437,7 +437,7 @@ func benchUpdate(b *testing.B, e binary.ByteOrder) *Trie {
 	k := make([]byte, 32)
 	for i := 0; i < b.N; i++ {
 		e.PutUint64(k, uint64(i))
-		trie.Update(k, k)
+		trie.UpdateIndexed(k, k, nil)
 	}
 	return trie
 }
@@ -447,7 +447,7 @@ func benchHash(b *testing.B, e binary.ByteOrder) {
 	k := make([]byte, 32)
 	for i := 0; i < benchElemCount; i++ {
 		e.PutUint64(k, uint64(i))
-		trie.Update(k, k)
+		trie.UpdateIndexed(k, k, nil)
 	}
 
 	b.ResetTimer()
@@ -473,7 +473,7 @@ func getString(trie *Trie, k string) []byte {
 }
 
 func updateString(trie *Trie, k, v string) {
-	trie.Update([]byte(k), []byte(v))
+	trie.UpdateIndexed([]byte(k), []byte(v), nil)
 }
 
 func deleteString(trie *Trie, k string) {