<init>

WindowSpecificationExpression(
    partitionBy: List<ScalarExpression<*>> = emptyList(),
    orderBy: List<OrderByExpression> = emptyList(),
    frameUnit: WindowFrameUnitType? = null,
    frameStart: WindowFrameBoundExpression? = null,
    frameEnd: WindowFrameBoundExpression? = null,
    isLeafNode: Boolean = false,
    extraProperties: Map<String, Any> = emptyMap())

Window specification expression.