Code review comment: No need for null check here

Code under review:
public void listExtensions(boolean all, String format, String search) throws IOException {
        final Map<String, Dependency> installed = findInstalled();

        Stream<Extension> extensionsStream = loadExtensions().stream();
        if (search != null && !"*".equalsIgnoreCase(search)) {
            final Pattern searchPattern = Pattern.compile(".*" + search + ".*", Pattern.CASE_INSENSITIVE);
            extensionsStream = extensionsStream.filter(e -> filterBySearch(searchPattern, e));
        }
        List<Extension> loadedExtensions = extensionsStream.collect(Collectors.toList());

        if (loadedExtensions.isEmpty()) {
            System.out.println("No extension found with this pattern");
        } else {
            String extensionStatus = all ? "available" : "installable";
            System.out.println(String.format("%nCurrent Quarkus extensions %s: ", extensionStatus));

            Consumer<String[]> currentFormatter;
            switch (format.toLowerCase()) {
                case "name":
                    currentFormatter = this::nameFormatter;
                    break;
                case "full":
                    currentFormatter = this::fullFormatter;
                    currentFormatter.accept(new String[] { "Status", "Extension", "ArtifactId", "Updated Version", "Guide" });
                    break;
                case "concise":
                default:
                    currentFormatter = this::conciseFormatter;
            }

            loadedExtensions.forEach(extension -> display(extension, installed, all, currentFormatter));

            if ("concise".equalsIgnoreCase(format)) {
                System.out.println("\nTo get more information, append -Dquarkus.extension.format=full to your command line.");
            }

            if (this.buildFile != null && this.buildFile instanceof GradleBuildFile) {
            	System.out.println("\nAdd an extension to your project by adding the dependency to your " +
                        "build.gradle or use `./gradlew addExtension --extensions=\"artifactId\"`");
            }
            else {
            	System.out.println("\nAdd an extension to your project by adding the dependency to your " +
                        "pom.xml or use `./mvnw quarkus:add-extension -Dextensions=\"artifactId\"`");
            }
        }
    }

Line commented on: if (this.buildFile != null && this.buildFile instanceof GradleBuildFile) {

Revised code:
public void listExtensions(boolean all, String format, String search) throws IOException {
        final Map<String, Dependency> installed = findInstalled();

        Stream<Extension> extensionsStream = loadExtensions().stream();
        if (search != null && !"*".equalsIgnoreCase(search)) {
            final Pattern searchPattern = Pattern.compile(".*" + search + ".*", Pattern.CASE_INSENSITIVE);
            extensionsStream = extensionsStream.filter(e -> filterBySearch(searchPattern, e));
        }
        List<Extension> loadedExtensions = extensionsStream.collect(Collectors.toList());

        if (loadedExtensions.isEmpty()) {
            System.out.println("No extension found with this pattern");
        } else {
            String extensionStatus = all ? "available" : "installable";
            System.out.println(String.format("%nCurrent Quarkus extensions %s: ", extensionStatus));

            Consumer<String[]> currentFormatter;
            switch (format.toLowerCase()) {
                case "name":
                    currentFormatter = this::nameFormatter;
                    break;
                case "full":
                    currentFormatter = this::fullFormatter;
                    currentFormatter.accept(new String[] { "Status", "Extension", "ArtifactId", "Updated Version", "Guide" });
                    break;
                case "concise":
                default:
                    currentFormatter = this::conciseFormatter;
            }

            loadedExtensions.forEach(extension -> display(extension, installed, all, currentFormatter));

            if ("concise".equalsIgnoreCase(format)) {
            	if (this.buildFile instanceof GradleBuildFile) {
            		System.out.println("\nTo get more information, append --format=full to your command line.");
            	}
            	else {
            		System.out.println("\nTo get more information, append -Dquarkus.extension.format=full to your command line.");
            	}
            }

            if (this.buildFile instanceof GradleBuildFile) {
            	System.out.println("\nAdd an extension to your project by adding the dependency to your " +
                        "build.gradle or use `./gradlew addExtension --extensions=\"artifactId\"`");
            }
            else {
            	System.out.println("\nAdd an extension to your project by adding the dependency to your " +
                        "pom.xml or use `./mvnw quarkus:add-extension -Dextensions=\"artifactId\"`");
            }
        }
    }