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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_resource_retriever(url):
 """ Get the appropriate retriever object for the specified url based on url scheme. Makes assumption that HTTP urls do not require any special authorization. For HTTP urls: returns HTTPResourceRetriever For s3:// urls returns S3ResourceRetriever :param url: url of the resource to be retrieved :return: ResourceRetriever object """


    if url.startswith('http://') or url.startswith('https://'):
        return HttpResourceRetriever(url)
    else:
        raise ValueError('Unsupported scheme in url: %s' % url)