code: @Override
      public PackageDoc containingPackage() {
          PackageDocImpl p = env.getPackageDoc(tsym.packge());
          if (p.setDocPath == false) {
              FileObject docPath;
              try {
                  Location location = env.fileManager.hasLocation(StandardLocation.SOURCE_PATH)
                      ? StandardLocation.SOURCE_PATH : StandardLocation.CLASS_PATH;
  
                  docPath = env.fileManager.getFileForInput(
                          location, p.qualifiedName(), "package.html");
              } catch (IOException e) {
                  docPath = null;
              }
  
              if (docPath == null) {
                  // fall back on older semantics of looking in same directory as
                  // source file for this class
                  SourcePosition po = position();
                  if (env.fileManager instanceof StandardJavaFileManager &&
                          po instanceof SourcePositionImpl) {
                      URI uri = ((SourcePositionImpl) po).filename.toUri();
                      if ("file".equals(uri.getScheme())) {
                          File f = new File(uri);
                          File dir = f.getParentFile();
                          if (dir != null) {
                              File pf = new File(dir, "package.html");
                              if (pf.exists()) {
                                  StandardJavaFileManager sfm = (StandardJavaFileManager) env.fileManager;
                                  docPath = sfm.getJavaFileObjects(pf).iterator().next();
                              }
                          }
  
                      }
                  }
              }
  
              p.setDocPath(docPath);
          }
          return p;
      }
docs: Return the package that this class is contained in.