
This change moves spyglass-plugin-xls's necessary exception definitions locally into the spyglass-plugin-xls project and changes their base to the SpyglassBaseException class. This change must be merged before Spyglass's exceptions may be consolidated. Related Change: https://review.opendev.org/#/c/667240/ Change-Id: I81c5ca2d9083aece3641bc8b5405dfd44baec810