@Override
    public DeclaredType visitType(TypeMirror value, Void unused) {
      return MoreTypes.asDeclared(value);
    }
Returns an {@link Equivalence} for {@link AnnotationValue} as annotation values may contain
{@link AnnotationMirror} instances some of whose implementations delegate equality tests to
{@link Object#equals} whereas the documentation explicitly states that instance/reference
equality is not the proper test.

@see AnnotationMirrors#equivalence()
common/src/main/java/com/google/auto/common/AnnotationValues.java