Fix type in SetHash.unset method
Fix type in SetHash.unset method

The previous version of this file inadvertently refereed to the
`unset` method as the `set` method.  This is now fixed.

tbrowder/doc,tbrowder/doc,MasterDuke17/doc,MasterDuke17/doc,MasterDuke17/doc,tbrowder/doc,tbrowder/doc,MasterDuke17/doc