Fix compilation errors

Author: ibbem

default.nix

@@ -137,6 +137,7 @@ pkgs.stdenvNoCC.mkDerivation rec {
   checkPhase = ''
     runHook preTest
 
+    # MAVEN_OPTS='-XX:+UnlockExperimentalVMOptions' mvn --offline -Dmaven.repo.local="$mavenRepo" test
     MAVEN_OPTS='-XX:+UnlockExperimentalVMOptions -XX:hashCode=2' mvn --offline -Dmaven.repo.local="$mavenRepo" test
 
     runHook postTest

src/test/java/GitDifferTest.java

@@ -93,7 +93,7 @@ public void testCase(TestCase testCase) throws IOException, DiffParseException {
         VariationDiff<DiffLinesLabel> variationDiff = GumTreeDiff.diffUsingMatching(beforeEdit, afterEdit, testCase.matcher());
 
         try (var output = IO.newBufferedOutputStream(testCase.actual())) {
-            new LineGraphExporter<>(new Format<>(new FullNodeFormat(), new ChildOrderEdgeFormat<>()))
+            new LineGraphExporter<DiffLinesLabel>(new Format<>(new FullNodeFormat(), new ChildOrderEdgeFormat<>()))
                     .exportVariationDiff(variationDiff, output);
         }
 
@@ -106,7 +106,7 @@ public void testCase(TestCase testCase) throws IOException, DiffParseException {
                 Files.delete(testCase.actual());
             } else {
                 // Keep output files if the test failed
-                new TikzExporter<>(new Format<>(new FullNodeFormat(), new DefaultEdgeLabelFormat<>()))
+                new TikzExporter<DiffLinesLabel>(new Format<>(new FullNodeFormat(), new DefaultEdgeLabelFormat<>()))
                         .exportFullLatexExample(variationDiff, testCase.visualisation());
                 fail(String.format(
                         "The diff of %s and %s is not as expected. " +