def _opt_call_to_base_type(self, value):
if not isinstance(value, _BaseValue):<EOL><INDENT>value = _BaseValue(self._call_to_base_type(value))<EOL><DEDENT>return value<EOL>
Call _to_base_type() if necessary.

        If the value is a _BaseValue instance, return it unchanged.
        Otherwise, call all _validate() and _to_base_type() methods and
        wrap it in a _BaseValue instance.