delete(index, length = 1) {
    if (this.doc !== null) {
      transact(this.doc, transaction => {
        typeListDelete(transaction, this, index, length);
      });
    } else {
      // @ts-ignore _prelimContent is defined because this is not yet integrated
      this._prelimContent.splice(index, length);
    }
  }
Deletes elements starting from an index.

@param {number} index Index at which to start deleting elements
@param {number} [length=1] The number of elements to remove. Defaults to 1.