def METHOD_NAME(self):
    # This mimic the model building with Backbone network
    layer = FeaturePyramid(min_level=2, max_level=5)
    c2 = keras.layers.Input([64, 64, 3])
    c3 = keras.layers.Input([32, 32, 3])
    c4 = keras.layers.Input([16, 16, 3])
    c5 = keras.layers.Input([8, 8, 3])
    inputs = {2: c2, 3: c3, 4: c4, 5: c5}
    output = layer(inputs)
    for level in inputs.keys():
        self.assertEquals(output[level].shape[1], inputs[level].shape[1])
        self.assertEquals(output[level].shape[2], inputs[level].shape[2])
        self.assertEquals(output[level].shape[3], layer.num_channels)