I have a question about external links... if I open a file, and
resource "/foo" is an external link, when I open it HDF5 goes out and
opens the file in which it resides. Is there some mechanism to
automatically close this file? I ask because as the user of "/foo" I
have no idea whether opening another file is going to be a side effect
of my accessing it. In practice, this leads to "leaks" of file
identifiers in my project (h5py).