from tensorflow.python.ops import math_ops

        # Create slots for the global solution.
        for v in var_list:
            self._zeros_slot(v, "vstar", self._name)
            self._zeros_slot(v, "gold", self._name)

    def _apply_dense(self, grad, var):
        lr_t = math_ops.cast(self._lr_t, var.dtype.base_dtype)
        mu_t = math_ops.cast(self._mu_t, var.dtype.base_dtype)
        
        vstar = self.get_slot(var, "vstar")
        gold = self.get_slot(var, "gold")

