Returns a blocker wrapper with the basics of the block header in place

def _generate_genesis_block(self):
        """
        Returns a blocker wrapper with the basics of the block header in place
        """
        genesis_header = block_pb2.BlockHeader(
            block_num=0,
            previous_block_id=NULL_BLOCK_IDENTIFIER,
            signer_public_key=self._identity_signer.get_public_key().as_hex())

        return BlockBuilder(genesis_header)