docs: def report_build_messages(self):
          """
          Checks environment variables to see whether pepper8 is run under a build agent such as TeamCity
          and performs the adequate actions to report statistics.
  
          Will not perform any action if HTML output is written to OUTPUT_FILE and not stdout.
          Currently only supports TeamCity.
  
          :return: A list of build message strings destined for stdout
          """
  
          if os.getenv('TEAMCITY_VERSION'):
              tc_build_message_warning = "##teamcity[buildStatisticValue key='pepper8warnings' value='{}']\n"
              tc_build_message_error = "##teamcity[buildStatisticValue key='pepper8errors' value='{}']\n"
  
              stdout.write(tc_build_message_warning.format(self.total_warnings))
              stdout.write(tc_build_message_error.format(self.total_errors))
              stdout.flush()