Defines the frame boundaries, from start (inclusive) to end (inclusive).
Both start and end are relative positions from the current row.
For example, “0” means “current row”, while “-1” means the row before
the current row, and “5” means the fifth row after the current row.
We recommend users use Window.unboundedPreceding, Window.unboundedFollowing,
and Window.currentRow to specify special boundary values, rather than using integral
New in version 1.4.0.
boundary start, inclusive.
The frame is unbounded if this is Window.unboundedPreceding, or
any value less than or equal to max(-sys.maxsize, -9223372036854775808).
boundary end, inclusive.
The frame is unbounded if this is Window.unboundedFollowing, or
any value greater than or equal to min(sys.maxsize, 9223372036854775807).