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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def make_model(self, output_file, add_curation_cols=False, up_only=False):
 """Export the statements into a tab-separated text file. Parameters output_file : str Name of the output file. add_curation_cols : bool Whether to add columns to facilitate statement curation. Default is False (no additional columns). up_only : bool Whether to include identifiers.org links *only* for the Uniprot grounding of an agent when one is available. Because most spreadsheets allow only a single hyperlink per cell, this can makes it easier to link to Uniprot information pages for curation purposes. Default is False. """

        stmt_header = ['INDEX', 'UUID', 'TYPE', 'STR',
                       'AG_A_TEXT', 'AG_A_LINKS', 'AG_A_STR',
                       'AG_B_TEXT', 'AG_B_LINKS', 'AG_B_STR',
                       'PMID', 'TEXT', 'IS_HYP', 'IS_DIRECT']
        if add_curation_cols:
            stmt_header = stmt_header + \
                          ['AG_A_IDS_CORRECT', 'AG_A_STATE_CORRECT',
                           'AG_B_IDS_CORRECT', 'AG_B_STATE_CORRECT',
                           'EVENT_CORRECT',
                           'RES_CORRECT', 'POS_CORRECT', 'SUBJ_ACT_CORRECT',
                           'OBJ_ACT_CORRECT', 'HYP_CORRECT', 'DIRECT_CORRECT']
        rows = [stmt_header]

        for ix, stmt in enumerate(self.statements):
            # Complexes
            if len(stmt.agent_list()) > 2:
                logger.info("Skipping statement with more than two members: %s"
                            % stmt)
                continue
            # Self-modifications, ActiveForms
            elif len(stmt.agent_list()) == 1:
                ag_a = stmt.agent_list()[0]
                ag_b = None
            # All others
            else:
                (ag_a, ag_b) = stmt.agent_list()
            # Put together the data row
            row = [ix+1, stmt.uuid, stmt.__class__.__name__, str(stmt)] + \
                  _format_agent_entries(ag_a, up_only) + \
                  _format_agent_entries(ag_b, up_only) + \
                  [stmt.evidence[0].pmid, stmt.evidence[0].text,
                   stmt.evidence[0].epistemics.get('hypothesis', ''),
                   stmt.evidence[0].epistemics.get('direct', '')]
            if add_curation_cols:
                row = row + ([''] * 11)
            rows.append(row)
        # Write to file
        write_unicode_csv(output_file, rows, delimiter='\t')