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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 qualified_name(self):
 """Get the qualified name of the variant. Returns: str: Name of the variant with version and index, eg "maya-2016.1[1]". """

        idxstr = '' if self.index is None else str(self.index)
        return "%s[%s]" % (self.qualified_package_name, idxstr)