code: public List<VirtualFile> getChildren() {
          // isDirectory does the read security check
          if (!isDirectory()) { return Collections.emptyList(); }
          final VFS.Mount mount = VFS.getMount(this);
          final Set<String> submounts = VFS.getSubmounts(this);
          final List<String> names = mount.getFileSystem().getDirectoryEntries(mount.getMountPoint(), this);
          final List<VirtualFile> virtualFiles = new ArrayList<VirtualFile>(names.size() + submounts.size());
          for (String name : names) {
              final VirtualFile child = new VirtualFile(name, this);
              virtualFiles.add(child);
              submounts.remove(name);
          }
          for (String name : submounts) {
              final VirtualFile child = new VirtualFile(name, this);
              virtualFiles.add(child);
          }
          return virtualFiles;
      }
docs: Get the children.  This is the combined list of real children within this directory, as well as virtual children
  created by submounts.
  
  @return the children