examples/demo_custom_tf_workflow.py/MyDense/build
class MyDense:    def build(self, input_shape):
        input_dim = input_shape[-1]
        w_shape = (input_dim, self.units)
        w_value = initializers.GlorotUniform()(w_shape)
        self.w = backend.Variable(w_value, name="kernel")

        b_shape = (self.units,)
        b_value = initializers.Zeros()(b_shape)
        self.b = backend.Variable(b_value, name="bias")