for dtype in [dtypes.half, dtypes.float32, dtypes.float64]:
      # train.GradientDescentOptimizer is V1 only API.
      with ops.Graph().as_default(), self.cached_session():
        var0 = variables.Variable([[1.0], [2.0]], dtype=dtype)
        var1 = variables.Variable([[3.0], [4.0]], dtype=dtype)