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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_url(method,
             api_url,
             api_version):
    '''
    Build the API URL.
    '''
    return '{url}/{version}/{method}.json'.format(url=api_url,
                                                  version=float(api_version),
                                                  method=method)