private static int randomIdNotInSet(Set<Integer> ids) {
      int id = 0;
      while (id == 0 || ids.contains(id)) {
        id = com.google.crypto.tink.internal.Util.randKeyId();
      }
      return id;
    }
Deletes the entry at index {@code i}. Shifts any subsequent entries to the left (subtracts
one from their indices).
java_src/src/main/java/com/google/crypto/tink/KeysetHandle.java