docs: def user_field(user, field, *args):
      """
      Gets or sets (optional) user model fields. No-op if fields do not exist.
      """
      if not field:
          return
      User = get_user_model()
      try:
          field_meta = User._meta.get_field(field)
          max_length = field_meta.max_length
      except FieldDoesNotExist:
          if not hasattr(user, field):
              return
          max_length = None
      if args:
          # Setter
          v = args[0]
          if v:
              v = v[0:max_length]
          setattr(user, field, v)
      else:
          # Getter
          return getattr(user, field)