Make return type more specific

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Indicate that SObject.getSOMClass is not later overwritten by SClass

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Simplify `newBlock()` method

These naive comments are not helpful at all (and wrong already)

Signed-off-by: Stefan Marr <git@stefan-marr.de>