code: function() {
      var OPERATORS =
          [[Blockly.Msg.TEXT_CHANGECASE_OPERATOR_UPPERCASE, 'UPPERCASE'],
           [Blockly.Msg.TEXT_CHANGECASE_OPERATOR_LOWERCASE, 'LOWERCASE'],
           [Blockly.Msg.TEXT_CHANGECASE_OPERATOR_TITLECASE, 'TITLECASE']];
      this.setHelpUrl(Blockly.Msg.TEXT_CHANGECASE_HELPURL);
      this.setColour(Blockly.Blocks.texts.HUE);
      this.appendValueInput('TEXT')
          .setCheck('String')
          .appendField(new Blockly.FieldDropdown(OPERATORS), 'CASE');
      this.setOutput(true, 'String');
      this.setTooltip(Blockly.Msg.TEXT_CHANGECASE_TOOLTIP);
    }
docs: Block for changing capitalization.
  @this Blockly.Block