private void GetMerkleBlockByHash(byte[] blockHash, Action <ErrorCode, MerkleBlock, UInt64> handler) { var managedHash = new hash_t { hash = blockHash }; IntPtr contextPtr = CreateContext(handler, managedHash); ChainNative.kth_chain_async_merkle_block_by_hash(nativeInstance_, contextPtr, managedHash, internalMerkleBlockGetHandlerByHash_); }