anchor.diff:                pessimisticType, declaredType)) {
               setAdditionalIncomingTypes([pessimisticType]);
               setInterfaceSafety(InterfaceSafety.semiTyped);
  -            instrumentation?.record(Uri.parse(cls.fileUri), fileOffset,
  -                'checkInterface', new InstrumentationValueLiteral('semiTyped'));
               if (!procedure.isAbstract && formalSafety == FormalSafety.safe) {
  -              formalSafety = FormalSafety.semiSafe;
  -              instrumentation?.record(Uri.parse(cls.fileUri), fileOffset,
  -                  'checkFormal', new InstrumentationValueLiteral('semiSafe'));
  +              setFormalSafety(FormalSafety.semiSafe);
               }
             }
           }
  
positive.code:         declaredFormal.isCovariant = true;
          if (declaredFormal.formalSafety != FormalSafety.unsafe) {
            declaredFormal.formalSafety = FormalSafety.unsafe;
            instrumentation?.record(
                Uri.parse(cls.fileUri),
                declaredFormal.fileOffset,
                'checkFormal',
                new InstrumentationValueLiteral('unsafe'));
          }
        }
        if (declaredIsAbstract) return;
  
negative.code:         addDeclaredAdditionalIncomingType(incomingType);
          if (formalSafety == FormalSafety.safe) {
            setFormalSafety(FormalSafety.semiSafe);
          }
        }
      }
  