def extend(self, schema):
if self._spl_type:<EOL><INDENT>raise TypeError("<STR_LIT>")<EOL><DEDENT>base = self.schema()<EOL>extends = schema.schema()<EOL>new_schema = base[:-<NUM_LIT:1>] + '<STR_LIT:U+002C>' + extends[<NUM_LIT:6>:]<EOL>return StreamSchema(new_schema)<EOL>
Extend a structured schema by another.

For example extending ``tuple<rstring id, timestamp ts, float64 value>``
with ``tuple<float32 score>`` results in ``tuple<rstring id, timestamp ts, float64 value, float32 score>``.

Args:
    schema(StreamSchema): Schema to extend this schema by.

Returns:
    StreamSchema: New schema that is an extension of this schema.