code: public static void eachDir(Path self, @ClosureParams(value = SimpleType.class, options = "java.nio.file.Path") Closure closure) throws IOException { // throws FileNotFoundException, IllegalArgumentException {
          eachFile(self, FileType.DIRECTORIES, closure);
      }
docs: Invokes the closure for each subdirectory in this directory,
  ignoring regular files.
  
  @param self    a Path (that happens to be a folder/directory)
  @param closure a closure (the parameter is the Path for the subdirectory file)
  @throws java.io.FileNotFoundException if the given directory does not exist
  @throws IllegalArgumentException      if the provided Path object does not represent a directory
  @see #eachFile(Path, groovy.io.FileType, groovy.lang.Closure)
  @since 2.3.0