this.appendDummyInput()
            .appendField(Blockly.Msg.VARIABLES_SET_TITLE)
            .appendField(new Blockly.FieldVariableArray(Blockly.Msg.SELECT_MENU, null, this), 'VAR')
            .appendField(new Blockly.FieldTextInput('0'), 'LENGTH_1')
            .appendField(new Blockly.FieldTextInput(''), 'LENGTH_2')