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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 config_add(self, key, value, **kwargs):
 """ Add a value to a key. Returns a list of warnings Conda may have emitted. """

        cmd_list = ['config', '--add', key, value]
        cmd_list.extend(self._setup_config_from_kwargs(kwargs))

        return self._call_and_parse(
            cmd_list,
            abspath=kwargs.get('abspath', True),
            callback=lambda o, e: o.get('warnings', []))