How to use the slate-react/lib/utils/offset-key.findKey function in slate-react

handleDragOverOtherNode = event => {
    if (!this.state.isDragging) {
      return
    }

    const targetDOMNode = event.target

    // As the event is registered on the editor parent node
    // ignore the event if it is coming from from the editor node itself
    if (targetDOMNode === this._editorNode) {
      return
    }

    const offsetKey = OffsetKey.findKey(targetDOMNode, 0)
    if (!offsetKey) {
      return
    }
    const {key} = offsetKey

    const {editor} = this.props
    const state = editor.getState()
    const {document} = state
    const range = createRange(event)

    if (range === null) {
      return
    }

    const {rangeIsAtStart, rangeOffset} = range

handleDragOverOtherNode = event => {
    if (!this.state.isDragging) {
      return
    }

    const targetDOMNode = event.target

    // As the event is registered on the editor parent node
    // ignore the event if it is coming from from the editor node itself
    if (targetDOMNode === this._editorNode) {
      this._dropTarget = null
      return
    }

    const offsetKey = OffsetKey.findKey(targetDOMNode, 0)
    if (!offsetKey) {
      return
    }
    const {key} = offsetKey

    // If this is 'our' node, return
    if (this.props.node.hasDescendant(key)) {
      return
    }

    const {editor} = this.props
    const state = editor.getState()
    const {document} = state

    const range = createRange(event)