diff --git a/trie_by_cid/helper/hasher.go b/trie_by_cid/helper/hasher.go
deleted file mode 100644
index feb5511..0000000
--- a/trie_by_cid/helper/hasher.go
+++ /dev/null
@@ -1,38 +0,0 @@
-package helper
-
-import (
-	"hash"
-
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/types"
-	"golang.org/x/crypto/sha3"
-)
-
-var _ types.TrieHasher = &testHasher{}
-
-// testHasher (copied from go-ethereum/core/types/block_test.go)
-// satisfies types.TrieHasher
-type testHasher struct {
-	hasher hash.Hash
-}
-
-func NewHasher() *testHasher {
-	return &testHasher{hasher: sha3.NewLegacyKeccak256()}
-}
-
-func (h *testHasher) Reset() {
-	h.hasher.Reset()
-}
-
-func (h *testHasher) Update(key, val []byte) error {
-	_, err := h.hasher.Write(key)
-	if err != nil {
-		return err
-	}
-	_, err = h.hasher.Write(val)
-	return err
-}
-
-func (h *testHasher) Hash() common.Hash {
-	return common.BytesToHash(h.hasher.Sum(nil))
-}
diff --git a/trie_by_cid/helper/statediff_helper.go b/trie_by_cid/helper/statediff_helper.go
deleted file mode 100644
index 0f0820b..0000000
--- a/trie_by_cid/helper/statediff_helper.go
+++ /dev/null
@@ -1,58 +0,0 @@
-package helper
-
-import (
-	"context"
-	"math/big"
-
-	"github.com/cerc-io/plugeth-statediff"
-	"github.com/cerc-io/plugeth-statediff/adapt"
-	"github.com/cerc-io/plugeth-statediff/indexer"
-	"github.com/cerc-io/plugeth-statediff/indexer/database/sql/postgres"
-	"github.com/cerc-io/plugeth-statediff/indexer/node"
-	"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/params"
-)
-
-var (
-	ChainConfig = params.TestChainConfig
-
-	mockTD = big.NewInt(1)
-)
-
-// IndexStateDiff indexes a single statediff.
-// - uses TestChainConfig
-// - block hash/number are left as zero
-func IndexStateDiff(dbConfig postgres.Config, stateCache state.Database, rootA, rootB common.Hash) error {
-	_, indexer, err := indexer.NewStateDiffIndexer(
-		context.Background(), ChainConfig, node.Info{}, dbConfig, true)
-	if err != nil {
-		return err
-	}
-	defer indexer.Close() // fixme: hangs when using PGX driver
-
-	builder := statediff.NewBuilder(adapt.GethStateView(stateCache))
-	block := types.NewBlock(&types.Header{Root: rootB}, nil, nil, nil, NewHasher())
-
-	// uses zero block hash/number, we only need the trie structure here
-	args := statediff.Args{
-		OldStateRoot: rootA,
-		NewStateRoot: rootB,
-	}
-	diff, err := builder.BuildStateDiffObject(args, statediff.Params{})
-	if err != nil {
-		return err
-	}
-	tx, err := indexer.PushBlock(block, nil, mockTD)
-	if err != nil {
-		return err
-	}
-	// we don't need to index diff.Nodes since we are just interested in the trie
-	for _, ipld := range diff.IPLDs {
-		if err := indexer.PushIPLD(tx, ipld); err != nil {
-			return err
-		}
-	}
-	return tx.Submit()
-}