code: def expand_families(stmts_in, **kwargs):
      
      from indra.tools.expand_families import Expander
      logger.info('Expanding families on %d statements...' % len(stmts_in))
      expander = Expander(hierarchies)
      stmts_out = expander.expand_families(stmts_in)
      logger.info('%d statements after expanding families...' % len(stmts_out))
      dump_pkl = kwargs.get('save')
      if dump_pkl:
          dump_statements(stmts_out, dump_pkl)
      return stmts_out
docs: Expand FamPlex Agents to individual genes.
  
      Parameters
      ----------
      stmts_in : list[indra.statements.Statement]
          A list of statements to expand.
      save : Optional[str]
          The name of a pickle file to save the results (stmts_out) into.
  
      Returns
      -------
      stmts_out : list[indra.statements.Statement]
          A list of expanded statements.