### Question:
RemoteValidatorApiHandler implements ValidatorApiChannel { @Override public SafeFuture<Optional<Attestation>> createUnsignedAttestation( final UInt64 slot, final int committeeIndex) { return asyncRunner.runAsync( () -> apiClient .createUnsignedAttestation(slot, committeeIndex) .map(tech.pegasys.teku.api.schema.Attestation::asInternalAttestation)); } RemoteValidatorApiHandler(final ServiceConfig config, final AsyncRunner asyncRunner); @VisibleForTesting  RemoteValidatorApiHandler(
      final ValidatorRestApiClient apiClient, final AsyncRunner asyncRunner); @Override SafeFuture<Optional<ForkInfo>> getForkInfo(); @Override SafeFuture<Optional<UInt64>> getGenesisTime(); @Override SafeFuture<Optional<List<ValidatorDuties>>> getDuties(
      final UInt64 epoch, final Collection<BLSPublicKey> publicKeys); @Override SafeFuture<Optional<List<AttesterDuties>>> getAttestationDuties(
      final UInt64 epoch, final Collection<Integer> validatorIndexes); @Override SafeFuture<Optional<List<ProposerDuties>>> getProposerDuties(final UInt64 epoch); @Override SafeFuture<Optional<Attestation>> createUnsignedAttestation(
      final UInt64 slot, final int committeeIndex); @Override void sendSignedAttestation(final Attestation attestation); @Override void sendSignedAttestation(
      final Attestation attestation, final Optional<Integer> validatorIndex); @Override SafeFuture<Optional<BeaconBlock>> createUnsignedBlock(
      final UInt64 slot, final BLSSignature randaoReveal, final Optional<Bytes32> graffiti); @Override void sendSignedBlock(final SignedBeaconBlock block); @Override SafeFuture<Optional<Attestation>> createAggregate(final Bytes32 attestationHashTreeRoot); @Override void sendAggregateAndProof(final SignedAggregateAndProof aggregateAndProof); @Override void subscribeToBeaconCommitteeForAggregation(
      final int committeeIndex, final UInt64 aggregationSlot); @Override void subscribeToPersistentSubnets(final Set<SubnetSubscription> subnetSubscriptions);  }### Answer:
@Test public void createUnsignedAttestation_WhenNone_ReturnsEmpty() { when(apiClient.createUnsignedAttestation(any(), anyInt())).thenReturn(Optional.empty()); SafeFuture<Optional<Attestation>> future = apiHandler.createUnsignedAttestation(UInt64.ONE, 0); assertThat(unwrapToOptional(future)).isEmpty(); }
@Test public void createUnsignedAttestation_WhenFound_ReturnsAttestation() { final Attestation attestation = dataStructureUtil.randomAttestation(); final tech.pegasys.teku.api.schema.Attestation schemaAttestation = new tech.pegasys.teku.api.schema.Attestation(attestation); when(apiClient.createUnsignedAttestation(eq(UInt64.ONE), eq(0))) .thenReturn(Optional.of(schemaAttestation)); SafeFuture<Optional<Attestation>> future = apiHandler.createUnsignedAttestation(UInt64.ONE, 0); assertThat(unwrapToValue(future)).usingRecursiveComparison().isEqualTo(attestation); }