def add_filter(self, filter):
if not isinstance(filter, AbstractFilter):<EOL><INDENT>err = '<STR_LIT>'.format(AbstractFilter)<EOL>raise InvalidFilter(err)<EOL><DEDENT>if filter not in self.filters:<EOL><INDENT>self.filters.append(filter)<EOL><DEDENT>return self<EOL>
Add filter to property
:param filter: object, extending from AbstractFilter
:return: None