presto-main/src/main/java/io/prestosql/operator/window/FrameInfo.java/FrameInfo/toString
class FrameInfo:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("type", type)
                .add("startType", startType)
                .add("startChannel", startChannel)
                .add("endType", endType)
                .add("endChannel", endChannel)
                .toString();
    }