context may be a callable or a dict.

def spawn(self, context=None):
        """
        context may be a callable or a dict.
        """
        if context is None:
            context = self.default_context

        if isinstance(context, collections.Callable):
            context = context()

        if not isinstance(context, collections.Mapping):
            raise PatchboardError('Cannot determine a valid context')

        return Client(self, context, self.api, self.endpoint_classes)