docs: def eth_getTransactionByBlockNumberAndIndex(self, block=BLOCK_TAG_LATEST,
                                                  index=0):
          """https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_gettransactionbyblocknumberandindex
  
          :param block: Block tag or number (optional)
          :type block: int or BLOCK_TAGS
  
          :param index: Index position (optional)
          :type index: int
  
          :return: transaction
          :rtype: dict or None
          """
          block = validate_block(block)
          result = yield from self.rpc_call('eth_getTransactionByBlockNumberAndIndex',
                                            [block, hex(index)])
          # TODO: Update result response
          return result