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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 build_backend(self, conn_string):
 """ Given a DSN, returns an instantiated backend class. Ex:: backend = gator.build_backend('locmem://') backend = gator.build_backend('redis://127.0.0.1:6379/0') :param conn_string: A DSN for connecting to the queue. Passed along to the backend. :type conn_string: string :returns: A backend ``Client`` instance """

        backend_name, _ = conn_string.split(':', 1)
        backend_path = 'alligator.backends.{}_backend'.format(backend_name)
        client_class = import_attr(backend_path, 'Client')
        return client_class(conn_string)