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

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