docs: public static IPath toFilterPath(String filePath, IProject project) {
          IPath path = new Path(filePath);
          IPath commonPath;
          if (project != null) {
              commonPath = project.getLocation();
              IPath relativePath = getRelativePath(path, commonPath);
              if (!relativePath.equals(path)) {
                  return relativePath;
              }
          }
          commonPath = ResourcesPlugin.getWorkspace().getRoot().getLocation();
          return getRelativePath(path, commonPath);
      }