Expression paged list Unit Test

Thanks to @antmdvs
Some scenarios need to add:

given totalCount > pageSize when page = 0 then should return pageSize elements
given totalCount > pageSize when page = 1 then should return results for page 1
other boundary conditions
a. totalCount = 0
a. page < 0
b. last page
c. page > # pages

Locate the Expression paged-list implementation and its existing unit-test file; no file path is named in the issue. Add tests for page 0 and page 1 when totalCount exceeds pageSize, plus totalCount 0, negative pages, the last page, and pages beyond the available range. Done means these boundary scenarios have clear passing assertions.

Written by the indexing model from the issue text.