code: function() {
      this.jsonInit({
        "message0": Blockly.Msg.LISTS_CREATE_EMPTY_TITLE,
        "output": "Array",
        "colour": Blockly.Blocks.lists.HUE,
        "tooltip": Blockly.Msg.LISTS_CREATE_EMPTY_TOOLTIP,
        "helpUrl": Blockly.Msg.LISTS_CREATE_EMPTY_HELPURL
      });
    }
docs: Block for creating an empty list.
  The 'list_create_with' block is preferred as it is more flexible.
  <block type="lists_create_with">
  <mutation items="0"></mutation>
  </block>
  @this Blockly.Block