public static boolean isType(TypeMirror type) {
    return type.accept(IsTypeVisitor.INSTANCE, null);
  }
Returns true if the raw type underlying the given {@link TypeMirror} represents a type that can
be referenced by a {@link Class}. If this returns true, then {@link #isTypeOf} is guaranteed to
not throw.
common/src/main/java/com/google/auto/common/MoreTypes.java