def source(self, request):
if isinstance(self.location, six.string_types):<EOL><INDENT>value = getattr(request, self.location, MultiDict())<EOL>if callable(value):<EOL><INDENT>value = value()<EOL><DEDENT>if value is not None:<EOL><INDENT>return value<EOL><DEDENT><DEDENT>else:<EOL><INDENT>values = MultiDict()<EOL>for l in self.location:<EOL><INDENT>value = getattr(request, l, None)<EOL>if callable(value):<EOL><INDENT>value = value()<EOL><DEDENT>if value is not None:<EOL><INDENT>values.update(value)<EOL><DEDENT><DEDENT>return values<EOL><DEDENT>return MultiDict()<EOL>
Pulls values off the request in the provided location
        :param request: The flask request object to parse arguments from