docs: private String formatElement(final Object element, final Map classMap) {
          StringBuffer buf = new StringBuffer("\tat ");
          buf.append(element);
          try {
              String className = getClassNameMethod.invoke(element, (Object[])null).toString();
              Object classDetails = classMap.get(className);
              if (classDetails != null) {
                  buf.append(classDetails);
              } else {
                  Class cls = findClass(className);
                  int detailStart = buf.length();
                  buf.append('[');
                  String mavenCoordinates = MavenCoordHelper.getMavenCoordinates(cls);
                  if (!Objects.isBlank(mavenCoordinates)) {
                      buf.append(mavenCoordinates);
                  } else {
                      try {
                          CodeSource source = cls.getProtectionDomain().getCodeSource();
                          if (source != null) {
                              URL locationURL = source.getLocation();
                              if (locationURL != null) {
                                  //
                                  //   if a file: URL
                                  //
                                  if ("file".equals(locationURL.getProtocol())) {
                                      String path = locationURL.getPath();
                                      if (path != null) {
                                          //
                                          //  find the last file separator character
                                          //
                                          int lastSlash = path.lastIndexOf('/');
                                          int lastBack = path.lastIndexOf(File.separatorChar);
                                          if (lastBack > lastSlash) {
                                              lastSlash = lastBack;
                                          }
                                          //
                                          //  if no separator or ends with separator (a directory)
                                          //     then output the URL, otherwise just the file name.
                                          //
                                          if (lastSlash <= 0 || lastSlash == path.length() - 1) {
                                              buf.append(locationURL);
                                          } else {
                                              buf.append(path.substring(lastSlash + 1));
                                          }
                                      }
                                  } else {
                                      buf.append(locationURL);
                                  }
                              }
                          }
                      } catch (SecurityException ex) {
                      }
                      buf.append(':');
                      Package pkg = cls.getPackage();
                      if (pkg != null) {
                          String implVersion = pkg.getImplementationVersion();
                          if (implVersion != null) {
                              buf.append(implVersion);
                          }
                      }
                  }
                  buf.append(']');
                  classMap.put(className, buf.substring(detailStart));
              }
          } catch (Exception ex) {
          }
          return buf.toString();
      }