private void GetMerkleBlockByHeight(UInt64 height, Action <ErrorCode, MerkleBlock, UInt64> handler)
{
GCHandle handlerHandle = GCHandle.Alloc(handler);
IntPtr handlerPtr = (IntPtr)handlerHandle;
ChainNative.kth_chain_async_merkle_block_by_height(nativeInstance_, handlerPtr, height, internalMerkleBlockGetHandler_);
}