How to use the scratch-blocks.Msg function in scratch-blocks

const menuFn = function () {
            const stageOptions = [
                [ScratchBlocks.Msg.SENSING_OF_BACKDROPNUMBER, 'backdrop #'],
                [ScratchBlocks.Msg.SENSING_OF_BACKDROPNAME, 'backdrop name'],
                [ScratchBlocks.Msg.SENSING_OF_VOLUME, 'volume']
            ];
            const spriteOptions = [
                [ScratchBlocks.Msg.SENSING_OF_XPOSITION, 'x position'],
                [ScratchBlocks.Msg.SENSING_OF_YPOSITION, 'y position'],
                [ScratchBlocks.Msg.SENSING_OF_DIRECTION, 'direction'],
                [ScratchBlocks.Msg.SENSING_OF_COSTUMENUMBER, 'costume #'],
                [ScratchBlocks.Msg.SENSING_OF_COSTUMENAME, 'costume name'],
                [ScratchBlocks.Msg.SENSING_OF_SIZE, 'size'],
                [ScratchBlocks.Msg.SENSING_OF_VOLUME, 'volume']
            ];
            if (vm.editingTarget) {
                let lookupBlocks = vm.editingTarget.blocks;
                let sensingOfBlock = lookupBlocks.getBlock(blockId);

                // The block doesn't exist, but should be in the flyout. Look there.
                if (!sensingOfBlock) {
                    sensingOfBlock = vm.runtime.flyoutBlocks.getBlock(blockId);
                    // If we still don't have a block, just return an empty list . This happens during
                    // scratch blocks construction.
                    if (!sensingOfBlock) {
                        return [['', '']];
                    }
                    // The block was in the flyout so look up future block info there.

ScratchBlocks.Blocks.event_whenbackdropswitchesto.init = function () {
        const json = jsonForHatBlockMenu(
            ScratchBlocks.Msg.EVENT_WHENBACKDROPSWITCHESTO,
            'BACKDROP', backdropNamesMenu, eventColors, []);
        this.jsonInit(json);
    };

const jsonForSensingMenus = function (menuOptionsFn) {
        return {
            message0: ScratchBlocks.Msg.SENSING_OF,
            args0: [
                {
                    type: 'field_dropdown',
                    name: 'PROPERTY',
                    options: function () {
                        return menuOptionsFn();
                    }

                },
                {
                    type: 'input_value',
                    name: 'OBJECT'
                }
            ],
            output: true,
            colour: ScratchBlocks.Colours.sensing.primary,

const menuFn = function () {
            const stageOptions = [
                [ScratchBlocks.Msg.SENSING_OF_BACKDROPNUMBER, 'backdrop #'],
                [ScratchBlocks.Msg.SENSING_OF_BACKDROPNAME, 'backdrop name'],
                [ScratchBlocks.Msg.SENSING_OF_VOLUME, 'volume']
            ];
            const spriteOptions = [
                [ScratchBlocks.Msg.SENSING_OF_XPOSITION, 'x position'],
                [ScratchBlocks.Msg.SENSING_OF_YPOSITION, 'y position'],
                [ScratchBlocks.Msg.SENSING_OF_DIRECTION, 'direction'],
                [ScratchBlocks.Msg.SENSING_OF_COSTUMENUMBER, 'costume #'],
                [ScratchBlocks.Msg.SENSING_OF_COSTUMENAME, 'costume name'],
                [ScratchBlocks.Msg.SENSING_OF_SIZE, 'size'],
                [ScratchBlocks.Msg.SENSING_OF_VOLUME, 'volume']
            ];
            if (vm.editingTarget) {
                let lookupBlocks = vm.editingTarget.blocks;
                let sensingOfBlock = lookupBlocks.getBlock(blockId);