judge the layer type.
    Returns:
        boolean -- True or False

def is_layer(layer, layer_type):
    '''judge the layer type.
    Returns:
        boolean -- True or False
    '''

    if layer_type == "Input":
        return isinstance(layer, StubInput)
    elif layer_type == "Conv":
        return isinstance(layer, StubConv)
    elif layer_type == "Dense":
        return isinstance(layer, (StubDense,))
    elif layer_type == "BatchNormalization":
        return isinstance(layer, (StubBatchNormalization,))
    elif layer_type == "Concatenate":
        return isinstance(layer, (StubConcatenate,))
    elif layer_type == "Add":
        return isinstance(layer, (StubAdd,))
    elif layer_type == "Pooling":
        return isinstance(layer, StubPooling)
    elif layer_type == "Dropout":
        return isinstance(layer, (StubDropout,))
    elif layer_type == "Softmax":
        return isinstance(layer, (StubSoftmax,))
    elif layer_type == "ReLU":
        return isinstance(layer, (StubReLU,))
    elif layer_type == "Flatten":
        return isinstance(layer, (StubFlatten,))
    elif layer_type == "GlobalAveragePooling":
        return isinstance(layer, StubGlobalPooling)