Sets 'value' into 'column' in 'record' in 'table'.

        This method is corresponding to the following ovs-vsctl command::

            $ ovs-vsctl set TBL REC COL[:KEY]=VALUE

def set_db_attribute(self, table, record, column, value, key=None):
        """
        Sets 'value' into 'column' in 'record' in 'table'.

        This method is corresponding to the following ovs-vsctl command::

            $ ovs-vsctl set TBL REC COL[:KEY]=VALUE
        """
        if key is not None:
            column = '%s:%s' % (column, key)
        command = ovs_vsctl.VSCtlCommand(
            'set', (table, record, '%s=%s' % (column, value)))
        self.run_command([command])