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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 setConnection(self, connection):
 """ Assigns the backend connection for this database instance. :param connection: <str> || <orb.Connection> """

        # define custom properties
        if not isinstance(connection, orb.Connection):
            conn = orb.Connection.byName(connection)
            if not conn:
                raise orb.errors.BackendNotFound(connection)
            connection = conn(self)
        else:
            connection.setDatabase(self)

        self.__connection = connection