@Test
  public void emptyRegistry_serializeKey_throws() throws Exception {
    MutableSerializationRegistry registry = new MutableSerializationRegistry();
    assertThat(registry.hasSerializerForKey(new TestKey1(), TestSerializationA.class)).isFalse();
    assertThrows(
        GeneralSecurityException.class,
        () -> registry
                .serializeKey(new TestKey1(), TestSerializationA.class, ACCESS));
  }
Tests for {@link MutableSerializationRegistry}.

<p>We repeat the main tests in SerializationRegistryTest. There really shouldn't be both classes,
but currently this is what we need, and the other is what we should have.
java_src/src/test/java/com/google/crypto/tink/internal/MutableSerializationRegistryTest.java