* we wanted to support legacy classes that implement the raw type {@code Comparable} (instead of
   * implementing {@code Comparable<Foo>}) without producing warnings. If so, we would prefer today
   * to produce warnings in that case, and we may change this method to do so in the future. Support
   * for raw {@code Comparable} types in Guava in general is tracked as <a

   * AnnotatedElement}, which {@code TypeVariable} began to extend only in Java 8. Those methods
   * refer only to types present in Java 7, so we could implement them in {@code TypeVariableImpl}
   * today. (We could probably then make {@code TypeVariableImpl} implement {@code AnnotatedElement}
   * so that we get partial compile-time checking.)
   *

 * supported by future versions of this library. However, serial forms generated by newer versions
 * of the code may not be readable by older versions of the code (e.g., a serialized Bloom filter
 * generated today may <i>not</i> be readable by a binary that was compiled 6 months ago).
 *
 * <p>As of Guava 23.0, this class is thread-safe and lock-free. It internally uses atomics and