Returns the keyword arguments for instantiating the form.

def get_form_kwargs(self):
        """
        Returns the keyword arguments for instantiating the form.
        """
        kwargs = {"initial": self.get_initial()}
        if self.request.method == "GET":
            kwargs.update({"data": self.request.GET})
        kwargs.update({"searchqueryset": self.get_query_set()})
        return kwargs