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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(self, key, help="", default=None, validator=None, converter=None, **kw):
 """ Add an option. @param key: the name of the variable, or a list or tuple of arguments @param help: optional help text for the options @param default: optional default value @param validator: optional function that is called to validate the option's value @type validator: Called with (key, value, environment) @param converter: optional function that is called to convert the option's value before putting it in the environment. """


        if SCons.Util.is_List(key) or isinstance(key, tuple):
            self._do_add(*key)
            return

        if not SCons.Util.is_String(key) or \
            not SCons.Environment.is_valid_construction_var(key):
                raise SCons.Errors.UserError("Illegal Variables.Add() key `%s'" % str(key))

        self._do_add(key, help, default, validator, converter)