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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def default_set(self, obj):
		'Set passed sink or source to be used as default one by pulseaudio server.'
		assert_pulse_object(obj)
		method = {
			PulseSinkInfo: self.sink_default_set,
			PulseSourceInfo: self.source_default_set }.get(type(obj))
		if not method: raise NotImplementedError(type(obj))
		method(obj)