docs: public String generateGraphVizDotFileFromClassDependencies() {
          if (isEmpty()) {
              throw new IllegalArgumentException("List is empty");
          }
          final ScanSpec scanSpec = get(0).scanResult.scanSpec;
          if (!scanSpec.enableInterClassDependencies) {
              throw new IllegalArgumentException(
                      "Please call ClassGraph#enableInterClassDependencies() before #scan()");
          }
          return GraphvizDotfileGenerator.generateGraphVizDotFileFromInterClassDependencies(this, 10.5f, 8.0f,
                  scanSpec.enableExternalClasses);
      }