@staticmethod<EOL><INDENT>def _get_list(values):<DEDENT>
if values is None:<EOL><INDENT>return []<EOL><DEDENT>elif isinstance(values, list):<EOL><INDENT>return values<EOL><DEDENT>else:<EOL><INDENT>return [values]<EOL><DEDENT>
Helper method that wraps values in a list. If the input is a list then it is returned. If the input is None then an empty list is returned. For anything else, the input value is wrapped as a single-element list.

:param values: Value to make sure exists in a list.
:return: List with the input values.