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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 get_prompt_tokens(self, _):
 """ returns prompt tokens """

        if self.shell_ctx.default_command:
            prompt = 'az {}>> '.format(self.shell_ctx.default_command)
        else:
            prompt = 'az>> '
        return [(Token.Az, prompt)]