def set_created_date(self, doc, created):
if not self.created_date_set:<EOL><INDENT>self.created_date_set = True<EOL>date = utils.datetime_from_iso_format(created)<EOL>if date is not None:<EOL><INDENT>doc.creation_info.created = date<EOL>return True<EOL><DEDENT>else:<EOL><INDENT>raise SPDXValueError('<STR_LIT>')<EOL><DEDENT><DEDENT>else:<EOL><INDENT>raise CardinalityError('<STR_LIT>')<EOL><DEDENT>
Sets created date, Raises CardinalityError if
        created date already set.
        Raises SPDXValueError if created is not a date.