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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 echo(self, args):
 """ An echo function An API test function which simply echoes what is is passed in the 'message' element in the args-dict.. Valid keys in the `args`-struct: * `auth` [struct] Authentication options passed to the :class:`AuthFactory`. * `message` [string] String to echo. * `sleep` [integer] Number of seconds to sleep before echoing. Returns a string. """

        if args.get('sleep'):
            time.sleep(args.get('sleep'))
        if args.get('message') is not None:
            return args.get('message')