def AddErrors(counts1, counts2):
 return ErrorCounts((counts1.fn + counts2.fn), (counts1.fp + counts2.fp), (counts1.truth_count + counts2.truth_count), (counts1.test_count + counts2.test_count))

def AddErrors ( counts1 , counts2 ) : return ErrorCounts ( ( counts1 . fn + counts2 . fn ) , ( counts1 . fp + counts2 . fp ) , ( counts1 . truth_count + counts2 . truth_count ) , ( counts1 . test_count + counts2 . test_count ) )
adds the counts and returns a new sum tuple .