Worksheet.FileFormat doesn't work with "SaveToStream" method

Hello,

Worksheet.SaveToStream method ignores the FileFormat property
While Worksheet.Save works fine unless I specify file extension which seems to override the FileFormat property.

@ibrahimahmed1985
Now Worksheet.SaveToStream method will save the file as xls file.
If you want to save the file as other format, please use Worksheet.Save method.