code: function() {
      this.jsonInit({
        "message0": Blockly.Msg.LOGIC_NULL,
        "output": null,
        "colour": Blockly.Blocks.logic.HUE,
        "tooltip": Blockly.Msg.LOGIC_NULL_TOOLTIP,
        "helpUrl": Blockly.Msg.LOGIC_NULL_HELPURL
      });
    }
docs: Block for null data type.
  @this Blockly.Block