docs: def _work_request(self, worker, md5=None):
          """Wrapper for a work_request to workbench"""
  
          # I'm sure there's a better way to do this
          if not md5 and not self.session.md5:
              return 'Must call worker with an md5 argument...'
          elif not md5:
              md5 = self.session.md5
  
          # Is the md5 a sample_set?
          if self.workbench.is_sample_set(md5):
              return self.workbench.set_work_request(worker, md5)
  
          # Make the work_request with worker and md5 args
          try:
              return self.workbench.work_request(worker, md5)
          except zerorpc.exceptions.RemoteError as e:
              return repr_to_str_decorator.r_to_s(self._data_not_found)(e)