code: def _get_description(self):
          
          return ", ".join([
              part for part in [
                  "missing: {}".format(self.missing) if self.missing else "",
                  (
                      "forbidden: {}".format(self.forbidden)
                      if self.forbidden else ""
                  ),
                  "invalid: {}:".format(self.invalid) if self.invalid else "",
                  (
                      "failed to parse: {}".format(self.failed)
                      if self.failed else ""
                  )
              ] if part
          ])
docs: Return human readable description error description.
  
          This description should explain everything that went wrong during
          deserialization.