'Test SchemeNode.'

def test_node(self):

    reg = small_testing_registry()
    file_desc = reg.widget('Orange.widgets.data.owfile.OWFile')
    node = SchemeNode(file_desc)
    inputs = node.input_channels()
    self.assertSequenceEqual(inputs, file_desc.inputs)
    for ch in inputs:
        channel = node.input_channel(ch.name)
        self.assertIsInstance(channel, InputSignal)
        self.assertTrue((channel in inputs))
    self.assertRaises(ValueError, node.input_channel, '%%&&&$$()[()[')
    outputs = node.output_channels()
    self.assertSequenceEqual(outputs, file_desc.outputs)
    for ch in outputs:
        channel = node.output_channel(ch.name)
        self.assertIsInstance(channel, OutputSignal)
        self.assertTrue((channel in outputs))
    self.assertRaises(ValueError, node.output_channel, '%%&&&$$()[()[')
