@property<EOL><INDENT>def submission_uuid(self):<DEDENT>
if self.submission is not None:<EOL><INDENT>return six.text_type(self.submission.uuid)<EOL><DEDENT>else:<EOL><INDENT>return None<EOL><DEDENT>
Retrieve the submission UUID associated with this score.
If the score isn't associated with a submission (for example, if this is
a "reset" score or a a non-courseware item like "class participation"),
then this will return None.

Returns:
    str or None