code: def extract_statements(self):
          
          for _, (tf, target, effect, refs) in self.df.iterrows():
              tf_agent = get_grounded_agent(tf)
              target_agent = get_grounded_agent(target)
              if effect == 'Activation':
                  stmt_cls = IncreaseAmount
              elif effect == 'Repression':
                  stmt_cls = DecreaseAmount
              else:
                  continue
              pmids = refs.split(';')
              for pmid in pmids:
                  stmt = make_stmt(stmt_cls, tf_agent, target_agent, pmid)
                  self.statements.append(stmt)
docs: Process the table to extract Statements.