get_worksheet_by_name method seem not working as expect

[luismiv85]

Hi! First at all thanks for this gem!

I'm trying to unify serveral exels in one. I have to merge every worksheet, then I try to find the worksheet with get_worksheet_by_name method, but always give me a new worksheet, never the existing one.

Some one with the same problem?

Thanks in advance!

[luismiv85]

Same behavior with constant_memory equal to false :(