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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 convert_1x_args(bucket, **kwargs):
 """ Converts arguments for 1.x constructors to their 2.x forms """

    host = kwargs.pop('host', 'localhost')
    port = kwargs.pop('port', None)
    if not 'connstr' in kwargs and 'connection_string' not in kwargs:
        kwargs['connection_string'] = _build_connstr(host, port, bucket)
    return kwargs