lead
open fun <T> ExpressionWithColumnType<T>.lead(offset: ExpressionWithColumnType<Int> = intLiteral(1), defaultValue: ExpressionWithColumnType<T>? = null): Lead<T>
Returns value evaluated at the row that is offset rows after the current row within the partition; if there is no such row, instead returns defaultValue. Both offset and defaultValue are evaluated with respect to the current row.