### Question:
KeyManagerImpl implements KeyManager<PrimitiveT> { @Override public final Class<PrimitiveT> getPrimitiveClass() { return primitiveClass; } KeyManagerImpl(
      KeyTypeManager<KeyProtoT> keyTypeManager, Class<PrimitiveT> primitiveClass); @Override final PrimitiveT getPrimitive(ByteString serializedKey); @Override final PrimitiveT getPrimitive(MessageLite key); @Override final MessageLite newKey(ByteString serializedKeyFormat); @Override final MessageLite newKey(MessageLite keyFormat); @Override final boolean doesSupport(String typeUrl); @Override final String getKeyType(); @Override int getVersion(); @Override final KeyData newKeyData(ByteString serializedKeyFormat); @Override final Class<PrimitiveT> getPrimitiveClass();  }### Answer:
@Test public void getPrimitiveClass() throws Exception { KeyManager<Aead> keyManager = new KeyManagerImpl<>(new TestKeyTypeManager(), Aead.class); assertThat(keyManager.getPrimitiveClass()).isEqualTo(Aead.class); }