getDistanceToNextChange(offset) {
        this.adjustNextEdit(offset);
        const nextEdit = this.edits[this.nextEditIdx];
        const nextChangeOffset = nextEdit ? this.translateOldToCur(nextEdit.offsetObj) : null;
        if (nextChangeOffset === null) {
            return null;
        }
        return lengthDiffNonNegative(offset, nextChangeOffset);
    }
@param offset Must be equal to or greater than the last offset this method has been called with.
Returns null if there is no edit anymore.