Description
Given a PageId, it returns the limits of the range of pages displayed.
While getOffsetByPageId() returns the offset of the data
within the current page, this method returns the offsets of the page numbers
interval.
E.g., in "Jumping" mode, if you have pageId=3 and
delta=10, it will return (1, 10).
pageID=8 would give you (1, 10) as well, because
1 <= 8 <= 10.
pageID=11 would give you (11, 20).
In "Sliding" mode, if you have pageId=5 and
delta=2, it will return (3, 7).
pageID of 9 would give you (4, 8).
if the method is called
without parameter, pageID is set to currentPage number
