@Test
  public void testBuilder_randomIdAfterFixedId_works() throws Exception {
    KeysetHandle handle =
        KeysetHandle.newBuilder()
            .addEntry(KeysetHandle.generateEntryFromParametersName("AES256_CMAC").withFixedId(777))
            .addEntry(
                KeysetHandle.generateEntryFromParametersName("AES256_CMAC")
                    .withRandomId()
                    .makePrimary())
            .build();
    assertThat(handle.size()).isEqualTo(2);
    assertThat(handle.getAt(0).getId()).isEqualTo(777);
  }
Tests that key parsing via the serialization registry works as expected.

<p>NOTE: This adds a parser to the MutableSerializationRegistry, which no other test uses.
java_src/src/test/java/com/google/crypto/tink/KeysetHandleTest.java