def __getitem__(self,key):
if isstring(key):
key = self.element._interfaceCluster.cord2pos(key)
if isiterable(key) and len(key) > 0:
o = self
for k in key:
if k:
if o == self:
o = SequenceInterface.__getitem__(self,k)
else:
o = o[k]
return o
else:
return SequenceInterface.__getitem__(self,key)
