Fix Sonar issue

Author: ComputerDaddyGuy

jfiletreeprettyprinter-core/src/main/java/io/github/computerdaddyguy/jfiletreeprettyprinter/options/PrettyPrintOptions.java

@@ -8,6 +8,7 @@
 import java.util.Objects;
 import java.util.function.Function;
 import java.util.function.ToIntFunction;
+import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
@@ -213,11 +214,11 @@ public PrettyPrintOptions filterFiles(@Nullable PathMatcher matcher) {
 	// ---------- Line extension ----------
 
 	@Nullable
-	private Function<Path, String> lineExtension;
+	private Function<@NonNull Path, @Nullable String> lineExtension;
 
 	@Override
 	@Nullable
-	public Function<Path, String> getLineExtension() {
+	public Function<@NonNull Path, @Nullable String> getLineExtension() {
 		return lineExtension;
 	}
 
@@ -237,7 +238,7 @@ public Function<Path, String> getLineExtension() {
 	 * @see LineExtensions
 	 * @see LineExtensionBuilder
 	 */
-	public PrettyPrintOptions withLineExtension(@Nullable Function<Path, String> lineExtension) {
+	public PrettyPrintOptions withLineExtension(@Nullable Function<@NonNull Path, @Nullable String> lineExtension) {
 		this.lineExtension = lineExtension;
 		return this;
 	}

jfiletreeprettyprinter-core/src/main/java/io/github/computerdaddyguy/jfiletreeprettyprinter/renderer/DefaultLineRenderer.java

@@ -8,7 +8,6 @@
 import java.util.List;
 import java.util.Objects;
 import org.jspecify.annotations.NullMarked;
-import org.jspecify.annotations.Nullable;
 
 @NullMarked
 class DefaultLineRenderer implements LineRenderer {
@@ -32,12 +31,12 @@ public String renderFile(Depth depth, FileEntry fileEntry) {
 	}
 
 	@Override
-	public @Nullable String renderChildLimitReached(Depth depth, SkippedChildrenEntry skippedChildrenEntry) {
+	public String renderChildLimitReached(Depth depth, SkippedChildrenEntry skippedChildrenEntry) {
 		return treeFormatter.format(depth) + fileFormatter.formatChildLimitReached(skippedChildrenEntry);
 	}
 
 	@Override
-	public @Nullable String renderMaxDepthReached(Depth depth, MaxDepthReachEntry maxDepthReachEntry) {
+	public String renderMaxDepthReached(Depth depth, MaxDepthReachEntry maxDepthReachEntry) {
 		return treeFormatter.format(depth) + fileFormatter.formatMaxDepthReached(maxDepthReachEntry);
 	}
 

jfiletreeprettyprinter-core/src/main/java/io/github/computerdaddyguy/jfiletreeprettyprinter/renderer/RenderingOptions.java

@@ -4,6 +4,7 @@
 import io.github.computerdaddyguy.jfiletreeprettyprinter.options.TreeFormat;
 import java.nio.file.Path;
 import java.util.function.Function;
+import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
@@ -33,6 +34,6 @@ public interface RenderingOptions {
 	 * @return
 	 */
 	@Nullable
-	Function<Path, String> getLineExtension();
+	Function<@NonNull Path, @Nullable String> getLineExtension();
 
 }