public static KeysetHandle read(KeysetReader reader)
      throws GeneralSecurityException, IOException {
    return KeysetHandle.fromKeyset(reader.read());
  }
@return a new {@link KeysetHandle} from a {@link Keyset} read with {@code reader}.
@throws GeneralSecurityException when the keyset is invalid or can't be read.
java_src/src/main/java/com/google/crypto/tink/CleartextKeysetHandle.java