code: private void addJarClasses(final Path location) {
          try (final JarFile jarFile = new JarFile(location.toFile())) {
              final Enumeration<JarEntry> entries = jarFile.entries();
              while (entries.hasMoreElements()) {
                  final JarEntry entry = entries.nextElement();
                  final String entryName = entry.getName();
                  if (entryName.endsWith(".class"))
                      classes.add(toQualifiedClassName(entryName));
              }
          } catch (IOException e) {
              throw new IllegalArgumentException("Could not read jar-file '" + location + "', reason: " + e.getMessage());
          }
      }
docs: Adds all classes in the given jar-file location to the set of known classes.
  
  @param location The location of the jar-file