TypeError: Text.isText is not a function

TypeError: Text.isText is not a function

我正在学习关于 https://docs.slatejs.org/walkthroughs/04-applying-custom-formatting

slate 教程

有一个函数调用Text.isText(n),我不断得到Type:Error Text.isText is not a function

toggleBoldMark(editor) {
    const isActive = CustomEditor.isBoldMarkActive(editor)
    Transforms.setNodes(
      editor,
      { bold: isActive ? null : true },
      { match: n => Text.isText(n), split: true }
    )
  },

尝试导入文本

import { Text } from 'slate';