private static String getAnnotationFqName(AnnotationMirror annotation) {
    return ((QualifiedNameable) annotation.getAnnotationType().asElement())
        .getQualifiedName()
        .toString();
  }
Returns the fully-qualified name of an annotation-mirror, e.g.
"com.google.auto.value.AutoValue".
value/src/main/java/com/google/auto/value/processor/AutoValueishProcessor.java