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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_drive_api(credentials):
 """ For a given set of credentials, return a drive API object. """

    http = httplib2.Http()
    http = credentials.authorize(http)
    service = discovery.build('drive', 'v2', http=http)
    service.credentials = credentials  # duck punch service obj. with credentials
    return service