def encode_to_stream(self, value: Row, out_stream: OutputStream):
# encode mask value
values = value.get_fields_by_names(self._field_names)
self._mask_utils.write_mask(values,
value.get_row_kind().value, out_stream)
# encode every field value
for i in range(self._field_count):
item = values[i]
if item is not None:
self._field_coders[i].encode_to_stream(item, out_stream)
