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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 downcase_hook(self, data: cmd2.plugin.PostparsingData) -> cmd2.plugin.PostparsingData: """A hook to make uppercase commands lowercase."""

        command = data.statement.command.lower()
        data.statement = self.statement_parser.parse("{} {}".format(
            command,
            '' if data.statement.args is None else data.statement.args
        ))
        return data