static String toString(AnnotationValue annotationValue) {
    StringBuilder sb = new StringBuilder();
    new SourceFormVisitor().visit(annotationValue, sb);
    return sb.toString();
  }
Returns a string representation of the given annotation value, suitable for inclusion in a Java
source file as the initializer of a variable of the appropriate type.
common/src/main/java/com/google/auto/common/AnnotationOutput.java