code: function(workspace) {
      var containerBlock = workspace.newBlock('controls_if_if');
      containerBlock.initSvg();
      var connection = containerBlock.nextConnection;
      for (var i = 1; i <= this.elseifCount_; i++) {
        var elseifBlock = workspace.newBlock('controls_if_elseif');
        elseifBlock.initSvg();
        connection.connect(elseifBlock.previousConnection);
        connection = elseifBlock.nextConnection;
      }
      if (this.elseCount_) {
        var elseBlock = workspace.newBlock('controls_if_else');
        elseBlock.initSvg();
        connection.connect(elseBlock.previousConnection);
      }
      return containerBlock;
    }
docs: Populate the mutator's dialog with this block's components.
  @param {!Blockly.Workspace} workspace Mutator's workspace.
  @return {!Blockly.Block} Root block in mutator.
  @this Blockly.Block