What is function/meaning of string arg to DataReferenceImpl()?

[Frank Gibbons <fgibbons@xxxxxxxxxxxxxxx>]

Can anyone tell me what the purpose of the string argument to 
DataReferenceImpl() is? I've seen it used in several programs like this 
Jython snippet:

t_h_ref = DataReferenceImpl("t_h_ref")

The point here is that string appears to be always the same as the name of 
variable in the programming language. Can be an arbitrary string? What is 
it used for? What happens if I leave it blank? How about if I use the same 
string for several variables? (like this Jython again)

t_h_ref = [] # Empty array
for i in range(10):
        t_h_ref.append(DataReferenceImpl("t_h_ref")

Thanks,

-Frank

PhD, Computational Biologist,
Harvard Medical School BCMP/SGM-322, 250 Longwood Ave, Boston MA 02115, USA.
Tel: 617-432-3555       Fax: 
617-432-3557       http://llama.med.harvard.edu/~fgibbons