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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 add(class_, name, value, sep=';'):
 		""" 		Add a value to a delimited variable, but only when the value isn't 		already present. 		"""

		values = class_.get_values_list(name, sep)
		if value in values:
			return
		new_value = sep.join(values + [value])
		winreg.SetValueEx(
			class_.key, name, 0, winreg.REG_EXPAND_SZ, new_value)
		class_.notify()