android/guava/src/com/google/common/base/internal/Finalizer.java
@NullableDecl
  private Method getFinalizeReferentMethod() {
    Class<?> finalizableReferenceClass = finalizableReferenceClassReference.get();
    if (finalizableReferenceClass == null) {
      /*
       * FinalizableReference's class loader was reclaimed. While there's a chance that other
       * finalizable references could be enqueued subsequently (at which point the class loader
       * would be resurrected by virtue of us having a strong reference to it), we should pretty
       * much just shut down and make sure we don't keep it alive any longer than necessary.
       */
      return null;
    }
    try {
      return finalizableReferenceClass.getMethod("finalizeReferent");
    } catch (NoSuchMethodException e) {
      throw new AssertionError(e);
    }
  }
@NullableDecl
  private Method getFinalizeReferentMethod() {
    Class<?> finalizableReferenceClass = finalizableReferenceClassReference.get();
    if (finalizableReferenceClass == null) {
      /*
       * FinalizableReference's class loader was reclaimed. While there's a chance that other
       * finalizable references could be enqueued subsequently (at which point the class loader
       * would be resurrected by virtue of us having a strong reference to it), we should pretty
       * much just shut down and make sure we don't keep it alive any longer than necessary.
       */
      return null;
    }
    try {
      return finalizableReferenceClass.getMethod("finalizeReferent");
    } catch (NoSuchMethodException e) {
      throw new AssertionError(e);
    }
  }
Looks up FinalizableReference.finalizeReferent() method.