code: def _detect(self):
          
          results = []
          for c in self.contracts:
              unindexed_params = self.detect_erc20_unindexed_event_params(c)
              if unindexed_params:
                  info = "{} ({}) does not mark important ERC20 parameters as 'indexed':\n"
                  info = info.format(c.name, c.source_mapping_str)
                  for (event, parameter) in unindexed_params:
                      info += "\t-{} ({}) does not index parameter '{}'\n".format(event.name, event.source_mapping_str, parameter.name)
  
                  # Add the events to the JSON (note: we do not add the params/vars as they have no source mapping).
                  json = self.generate_json_result(info)
                  self.add_functions_to_json([event for event, _ in unindexed_params], json)
                  results.append(json)
  
          return results
docs: Detect un-indexed ERC20 event parameters in all contracts.