@Nullable
    @Override
    public abstract String obtain();

    @Override
    public abstract String getDisplayName();

    @Nullable
    protected String propertyNameOrNull() {
        return getParameters().getPropertyName().getOrNull();
    }

    }

    public static String extractMethodDescriptor(ExecutableElement methodElement) {
        return Type.getMethodDescriptor(
            extractReturnType(methodElement),
            methodElement.getParameters().stream().map(it -> extractType(it.asType())).toArray(Type[]::new)
        );
    }

            abstract Property<WebServer> getServer();
        }

        @Override
        public void execute() {
            // Use the server to download a file
            WebServer server = getParameters().getServer().get();
            URI uri = server.getUri().resolve("somefile.zip");
            System.out.println(String.format("Downloading %s", uri));
        }
    }

    @Inject

        DirectoryProperty getResources();
    }

    private final URI uri;

    public WebServer() throws URISyntaxException {
        // Use the parameters
        int port = getParameters().getPort().get();
        uri = new URI(String.format("https://localhost:%d/", port));

        // Start the server ...

        System.out.println(String.format("Server is running at %s", uri));
    }

        DirectoryProperty getResources();
    }

    private final URI uri;

    public WebServer() throws URISyntaxException {
        // Use the parameters
        int port = getParameters().getPort().get();
        uri = new URI(String.format("https://localhost:%d/", port));

        // Start the server ...

        System.out.println(String.format("Server is running at %s", uri));
    }

            }
        }
        return buffer.toString();
    }

    public MojoDescriptor getMojoDescriptor() {
        return mojo;
    }

    public List<Parameter> getParameters() {
        return parameters;
    }

    private static void decomposeParameterIntoUserInstructions(
            MojoDescriptor mojo, Parameter param, StringBuilder messageBuffer) {

    }

    @Override
    public Iterable<Dependency> getImplementationDependencies() {
        return ImmutableSet.of(getDependencyFactory().create(GROUP_NAME + ":" + getParameters().getVersion().get()));
    }

    }

    @Override
    public String getDisplayName() {
        return String.format("environment variable '%s'", variableNameOrNull());
    }

    private String variableNameOrNull() {
        return getParameters().getVariableName().getOrNull();
    }

    @Override
    public Iterable<Dependency> getImplementationDependencies() {
        return Collections.singletonList(getDependencyFactory().create(GROUP_NAME + ":" + getParameters().getJupiterVersion().get()));
    }

        }

        MojoDescriptor mojoDescriptor = mojoExecution.getMojoDescriptor();

        // in first step get parameter names of current goal
        Set<String> parametersNamesGoal = mojoDescriptor.getParameters().stream()
                .flatMap(this::getParameterNames)
                .collect(Collectors.toSet());

        Set<String> unknownParameters = getUnknownParameters(mojoExecution, parametersNamesGoal);