diff --git a/core/state/dump.go b/core/state/dump.go
index 0218e723ef..00aeb4f173 100644
--- a/core/state/dump.go
+++ b/core/state/dump.go
@@ -28,6 +28,14 @@ import (
 	"github.com/XinFinOrg/XDPoSChain/trie"
 )
 
+// DumpCollector interface which the state trie calls during iteration
+type DumpCollector interface {
+	// OnRoot is called with the state root
+	OnRoot(common.Hash)
+	// OnAccount is called once for each account in the trie
+	OnAccount(common.Address, DumpAccount)
+}
+
 // DumpAccount represents an account in the state.
 type DumpAccount struct {
 	Balance   string                 `json:"balance"`
@@ -46,9 +54,14 @@ type Dump struct {
 	Accounts map[common.Address]DumpAccount `json:"accounts"`
 }
 
-// iterativeDump is a 'collector'-implementation which dump output line-by-line iteratively.
-type iterativeDump struct {
-	*json.Encoder
+// OnRoot implements DumpCollector interface
+func (d *Dump) OnRoot(root common.Hash) {
+	d.Root = fmt.Sprintf("%x", root)
+}
+
+// OnAccount implements DumpCollector interface
+func (d *Dump) OnAccount(addr common.Address, account DumpAccount) {
+	d.Accounts[addr] = account
 }
 
 // IteratorDump is an implementation for iterating over data.
@@ -58,28 +71,23 @@ type IteratorDump struct {
 	Next     []byte                         `json:"next,omitempty"` // nil if no more accounts
 }
 
-// Collector interface which the state trie calls during iteration
-type collector interface {
-	onRoot(common.Hash)
-	onAccount(common.Address, DumpAccount)
-}
-
-func (d *Dump) onRoot(root common.Hash) {
+// OnRoot implements DumpCollector interface
+func (d *IteratorDump) OnRoot(root common.Hash) {
 	d.Root = fmt.Sprintf("%x", root)
 }
 
-func (d *Dump) onAccount(addr common.Address, account DumpAccount) {
-	d.Accounts[addr] = account
-}
-func (d *IteratorDump) onRoot(root common.Hash) {
-	d.Root = fmt.Sprintf("%x", root)
-}
-
-func (d *IteratorDump) onAccount(addr common.Address, account DumpAccount) {
+// OnAccount implements DumpCollector interface
+func (d *IteratorDump) OnAccount(addr common.Address, account DumpAccount) {
 	d.Accounts[addr] = account
 }
 
-func (d iterativeDump) onAccount(addr common.Address, account DumpAccount) {
+// iterativeDump is a DumpCollector-implementation which dumps output line-by-line iteratively.
+type iterativeDump struct {
+	*json.Encoder
+}
+
+// OnAccount implements DumpCollector interface
+func (d iterativeDump) OnAccount(addr common.Address, account DumpAccount) {
 	dumpAccount := &DumpAccount{
 		Balance:   account.Balance,
 		Nonce:     account.Nonce,
@@ -96,15 +104,16 @@ func (d iterativeDump) onAccount(addr common.Address, account DumpAccount) {
 	d.Encode(dumpAccount)
 }
 
-func (d iterativeDump) onRoot(root common.Hash) {
+// OnRoot implements DumpCollector interface
+func (d iterativeDump) OnRoot(root common.Hash) {
 	d.Encode(struct {
 		Root common.Hash `json:"root"`
 	}{root})
 }
 
-func (s *StateDB) dump(c collector, excludeCode, excludeStorage, excludeMissingPreimages bool, start []byte, maxResults int) (nextKey []byte) {
+func (s *StateDB) DumpToCollector(c DumpCollector, excludeCode, excludeStorage, excludeMissingPreimages bool, start []byte, maxResults int) (nextKey []byte) {
 	missingPreimages := 0
-	c.onRoot(s.trie.Hash())
+	c.OnRoot(s.trie.Hash())
 
 	var count int
 	it := trie.NewIterator(s.trie.NodeIterator(start))
@@ -145,7 +154,7 @@ func (s *StateDB) dump(c collector, excludeCode, excludeStorage, excludeMissingP
 				account.Storage[common.BytesToHash(s.trie.GetKey(storageIt.Key))] = common.Bytes2Hex(content)
 			}
 		}
-		c.onAccount(addr, account)
+		c.OnAccount(addr, account)
 		count++
 		if maxResults > 0 && count >= maxResults {
 			if it.Next() {
@@ -166,7 +175,7 @@ func (s *StateDB) RawDump(excludeCode, excludeStorage, excludeMissingPreimages b
 	dump := &Dump{
 		Accounts: make(map[common.Address]DumpAccount),
 	}
-	s.dump(dump, excludeCode, excludeStorage, excludeMissingPreimages, nil, 0)
+	s.DumpToCollector(dump, excludeCode, excludeStorage, excludeMissingPreimages, nil, 0)
 	return *dump
 }
 
@@ -175,14 +184,14 @@ func (s *StateDB) Dump(excludeCode, excludeStorage, excludeMissingPreimages bool
 	dump := s.RawDump(excludeCode, excludeStorage, excludeMissingPreimages)
 	json, err := json.MarshalIndent(dump, "", "    ")
 	if err != nil {
-		fmt.Println("dump err", err)
+		fmt.Println("Dump err", err)
 	}
 	return json
 }
 
 // IterativeDump dumps out accounts as json-objects, delimited by linebreaks on stdout
 func (s *StateDB) IterativeDump(excludeCode, excludeStorage, excludeMissingPreimages bool, output *json.Encoder) {
-	s.dump(iterativeDump{output}, excludeCode, excludeStorage, excludeMissingPreimages, nil, 0)
+	s.DumpToCollector(iterativeDump{output}, excludeCode, excludeStorage, excludeMissingPreimages, nil, 0)
 }
 
 // IteratorDump dumps out a batch of accounts starts with the given start key
@@ -190,6 +199,6 @@ func (s *StateDB) IteratorDump(excludeCode, excludeStorage, excludeMissingPreima
 	iterator := &IteratorDump{
 		Accounts: make(map[common.Address]DumpAccount),
 	}
-	iterator.Next = s.dump(iterator, excludeCode, excludeStorage, excludeMissingPreimages, start, maxResults)
+	iterator.Next = s.DumpToCollector(iterator, excludeCode, excludeStorage, excludeMissingPreimages, start, maxResults)
 	return *iterator
 }
diff --git a/core/state/state_test.go b/core/state/state_test.go
index 4b312619d7..98d45231c2 100644
--- a/core/state/state_test.go
+++ b/core/state/state_test.go
@@ -57,7 +57,7 @@ func TestDump(t *testing.T) {
 	s.state.updateStateObject(obj2)
 	s.state.Commit(false)
 
-	// check that dump contains the state objects that are in trie
+	// check that DumpToCollector contains the state objects that are in trie
 	got := string(s.state.Dump(false, false, true))
 	want := `{
     "root": "71edff0130dd2385947095001c73d9e28d862fc286fca2b922ca6f6f3cddfdd2",
@@ -84,7 +84,7 @@ func TestDump(t *testing.T) {
     }
 }`
 	if got != want {
-		t.Errorf("dump mismatch:\ngot: %s\nwant: %s\n", got, want)
+		t.Errorf("DumpToCollector mismatch:\ngot: %s\nwant: %s\n", got, want)
 	}
 }