code: def _generate_genesis_block(self):
          
          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)
docs: Returns a blocker wrapper with the basics of the block header in place