docs: def in_field(self, field_name, *field_vals, **field_kwargs):
          """
          field_vals -- list -- a list of field_val values
          """
          field_name = self._normalize_field_name(field_name)
          fv = make_list(field_vals[0]) if field_vals else None
          if field_kwargs:
              for k in field_kwargs:
                  if not field_kwargs[k]:
                      raise ValueError("Cannot IN an empty list")
  
                  field_kwargs[k] = make_list(field_kwargs[k])
  
          else:
              if not fv: self.can_get = False
  
          self.fields_where.append(field_name, ["in", field_name, fv, field_kwargs])
          return self