How to use the roosterjs-editor-dom.Position.getStart function in roosterjs-editor-dom

}
            break;
        case ContentPosition.Range:
        case ContentPosition.SelectionStart:
            let { range, rangeToRestore } = getInitialRange(core, option);

            if (!range) {
                return;
            }

            // if to replace the selection and the selection is not collapsed, remove the the content at selection first
            if (option.replaceSelection && !range.collapsed) {
                range.deleteContents();
            }

            let pos = Position.getStart(range);
            let blockElement: BlockElement;

            if (
                option.insertOnNewLine &&
                (blockElement = getBlockElementAtNode(contentDiv, pos.normalize().node))
            ) {
                pos = new Position(blockElement.getEndNode(), PositionType.After);
            } else {
                pos = adjustNodeInsertPosition(contentDiv, node, pos);
            }

            let nodeForCursor = node.nodeType == NodeType.DocumentFragment ? node.lastChild : node;
            range = createRange(pos);
            range.insertNode(node);
            if (option.updateCursor && nodeForCursor) {
                rangeToRestore = createRange(

return cacheGetEventData(event, 'FIRST_STRUCTURE', () => {
        // Provide a chance to keep browser default behavior by pressing SHIFT
        let element = event.rawEvent.shiftKey ? null : editor.getElementAtCursor(CHILD_SELECTOR);

        if (element) {
            let range = editor.getSelectionRange();
            if (
                range &&
                range.collapsed &&
                isPositionAtBeginningOf(Position.getStart(range), element) &&
                !editor.getBodyTraverser(element).getPreviousBlockElement()
            ) {
                return editor.getElementAtCursor(CHILD_PARENT_TAG_MAP[getTagOfNode(element)]);
            }
        }

        return null;
    });
}

break;
        case ContentPosition.Range:
        case ContentPosition.SelectionStart:
            let { range, rangeToRestore } = getInitialRange(core, option);

            if (!range) {
                return;
            }

            // if to replace the selection and the selection is not collapsed, remove the the content at selection first
            if (option.replaceSelection && !range.collapsed) {
                range.deleteContents();
            }

            let pos = Position.getStart(range);
            let blockElement: BlockElement;

            if (
                option.insertOnNewLine &&
                (blockElement = getBlockElementAtNode(contentDiv, pos.normalize().node))
            ) {
                pos = new Position(blockElement.getEndNode(), PositionType.After);
            } else {
                pos = adjustNodeInsertPosition(contentDiv, node, pos);
            }

            let nodeForCursor = node.nodeType == NodeType.DocumentFragment ? node.lastChild : node;
            range = createRange(pos);
            range.insertNode(node);
            if (option.updateCursor && nodeForCursor) {
                rangeToRestore = createRange(

export function getStyleBasedFormatState(editor: Editor): StyleBasedFormatState {
    let range = editor.getSelectionRange();
    let node = range && Position.getStart(range).normalize().node;
    let styles = node ? getComputedStyles(node) : [];
    return {
        fontName: styles[0],
        fontSize: styles[1],
        textColor: styles[2],
        backgroundColor: styles[3],
    };
}

core: EditorCore,
    callback: (start: NodePosition, end: NodePosition, snapshotBeforeCallback: string) => any,
    changeSource: ChangeSource | string
) => {
    let isNested = core.currentUndoSnapshot !== null;
    let data: any;

    if (!isNested) {
        core.currentUndoSnapshot = core.corePlugins.undo.addUndoSnapshot();
    }

    try {
        if (callback) {
            let range = core.api.getSelectionRange(core, true /*tryGetFromCache*/);
            data = callback(
                range && Position.getStart(range).normalize(),
                range && Position.getEnd(range).normalize(),
                core.currentUndoSnapshot
            );

            if (!isNested) {
                core.corePlugins.undo.addUndoSnapshot();
            }
        }
    } finally {
        if (!isNested) {
            core.currentUndoSnapshot = null;
        }
    }

    if (callback && changeSource) {
        let event: ContentChangedEvent = {

private tryNormalizeTyping(event: PluginKeyboardEvent, range?: Range) {
        let position = this.ensureTypeInElement(
            Position.getStart(range || this.editor.getSelectionRange()),
            event
        );
        this.editor.select(position);
    }