### Question:
PublicKeyCredentialDescriptor implements Comparable<PublicKeyCredentialDescriptor> { public static PublicKeyCredentialDescriptorBuilder.MandatoryStages builder() { return new PublicKeyCredentialDescriptorBuilder.MandatoryStages(); } @JsonCreator private  PublicKeyCredentialDescriptor(
        @NonNull @JsonProperty("type") PublicKeyCredentialType type,
        @NonNull @JsonProperty("id") ByteArray id,
        @JsonProperty("transports") Set<AuthenticatorTransport> transports
    ); @Override int compareTo(PublicKeyCredentialDescriptor other); static PublicKeyCredentialDescriptorBuilder.MandatoryStages builder(); Optional<SortedSet<AuthenticatorTransport>> getTransports();  }### Answer:
@Test(expected = NullPointerException.class) public void itHasTheseBuilderMethods() { PublicKeyCredentialDescriptor.builder() .id(null) .transports(Collections.emptySet()) .transports(Optional.of(Collections.emptySet())) ; }