sclass mapI_closeable_It extends CloseableIterableIterator {
  O f;
  CloseableIterableIterator i;
  
  *() {}
  *(O *f, CloseableIterableIterator *i) {}
  
  public bool hasNext() {
    ret i.hasNext();
  }
  
  public O next() {
    ret callF(f, i.next());
  }
  
  toString {
    ret formatFunctionCall('mapI_closeable, f, i);
  }
  
  public void close() throws Exception {
    i.close();
  }
}

static CloseableIterableIterator mapLike mapI_closeable(final O f, final CloseableIterableIterator i) {
  ret mapI_closeable_It(f, i);
}

Began life as a copy of #1004292