code: def get_bel_stmts(self, filter=False):
          if self.basename is not None:
              bel_stmt_path = '%s_bel_stmts.pkl' % self.basename
          if self.basename is not None and os.path.isfile(bel_stmt_path):
              logger.info("Loading BEL statements from %s" % bel_stmt_path)
              with open(bel_stmt_path, 'rb') as f:
                  bel_statements = pickle.load(f)
          else:
              bel_proc = bel.process_pybel_neighborhood(self.gene_list,
                  network_file=self.bel_corpus)
              bel_statements = bel_proc.statements
              if self.basename is not None:
                  with open(bel_stmt_path, 'wb') as f:
                      pickle.dump(bel_statements, f)
          if filter:
              if len(self.gene_list) > 1:
                  bel_statements = ac.filter_gene_list(bel_statements,
                                                       self.gene_list, 'all')
          return bel_statements