How to use the react-native-cn-richtext-editor.convertToObject function in react-native-cn-richtext-editor

constructor(props) {
        super(props);
        this.customStyles = {...defaultStyles, body: {fontSize: 12}, heading : {fontSize: 16}
        , title : {fontSize: 20}, ol : {fontSize: 12 }, ul: {fontSize: 12}, bold: {fontSize: 12, fontWeight: 'bold', color: ''}
        };  
        this.state = {
            selectedTag : 'body',
            selectedColor : 'default',
            selectedHighlight: 'default',
            colors : ['red', 'green', 'blue'],
            highlights:['yellow_hl','pink_hl', 'orange_hl', 'green_hl','purple_hl','blue_hl'],
            selectedStyles : [],
            // value: [getInitialObject()] get empty editor
            value: convertToObject('<div><p><span>This is </span><span style="font-weight: bold;">bold</span><span> and </span><span style="font-style: italic;">italic </span><span>text</span></p></div>'
            , this.customStyles)
        };
        
        this.editor = null;

    }