我正在尝试使用UnitControl 在自定义Gutenberg块中定义文本的行高。我收到；此块遇到错误，无法预览；当我尝试访问WordPress编辑器中的块时。我不确定是什么导致了这个错误。我甚至尝试在返回中删除对UnitControl的引用，并保存如下lineHeight:headlineSpacing 查看是否会停止标记错误。它仍然会给我错误，所以我不确定我是否正确使用了UnitControl，或者我是否在<UnitControl> 要素

CODE:

const { registerBlockType } = wp.blocks;
const { 
    RichText, 
    InspectorControls, 
    ColorPalette,
    MediaUpload,
    MediaUploadCheck,
    Button,
    RawHTML,
    FontSizePicker,
    __experimentalUnitControl,
    InnerBlocks
} = wp.blockEditor;

const { PanelBody, IconButton } = wp.components;

registerBlockType(\'mycustomsite/small-jumbo\', {
    //Built-in Attributes
    title: \'Small Jumbo\',
    description: \'Block to generate a smaller jumbotron\',
    icon: \'align-full-width\',
    category: \'design\',

    //Custom Attributes
    attributes: {
        title: {
        type: \'string\',
        source: \'html\',
        selector: \'h1\'
        }
    },

    //Built-in Functions
    edit({attributes, setAttributes}) {
        const{
            title,
            headlineSize,
            headlineSpacing,
        } = attributes;

        const headlineSizes = [
            {
                name: \'14px\',
                slug: \'fourteen\',
                size: 14
            },
            {
                name: \'16px\',
                slug: \'sixteen\',
                size: 16
            },
            {
                name: \'18px\',
                slug: \'eighteen\',
                size: 18
            },
            {
                name: \'24px\',
                slug: \'twentyfour\',
                size: 24
            }
        ];

        //Custom Functions

        function onChangeTitle(newTitle) {
            setAttributes( { title: newTitle } );
        }

        function onChangeHeadlineSize( newHeadlineSize ) {
            setAttributes( { headlineSize: newHeadlineSize } );
        }

        function onChangeHeadlineSpacing( newHeadlineSpacing) {
            setAttributes( { headlineSize: newHeadlineSpacing } );
        }

        return ([
            <InspectorControls style={ { marginBottom: \'40px\' } }>
                <p><strong>Customize Top Text</strong></p>
                <PanelBody title={ \'Headline Size\' }>
                    <FontSizePicker
                        fontSizes={ headlineSizes }
                        value={ headlineSize }
                        onChange={ onChangeHeadlineSize }
                    />
                    </PanelBody>
                    <PanelBody title={ \'Line Height\' }>
                    <UnitControl
                        label="Line Height"
                        isUnitSelectTabbable
                        value={ headlineSpacing } 
                        onChange={ onChangeHeadlineSpacing }
                    />
                </PanelBody>
            </InspectorControls>,

        <div> 
            <RichText 
                key="editable"
                tagName="h1"
                placeholder="H1 Title" 
                value= { title }
                onChange= { onChangeTitle }
                style= { { fontSize:headlineSize, lineHeight:headlineSpacing} }
            />
        </div>
        ]);
    },

    save({ attributes }) {
        const {
        title,
        headlineSize,
        headlineSpacing,
        } = attributes;

        return (
            <div>
                <RichText.Content style={ {fontSize:headlineSize, lineHeight:headlineSpacing } } tagName="h1" value={title} />
            </div>
        );
    }
});