def __setitem__(self, index, val):
if val == self[index]:<EOL><INDENT>return<EOL><DEDENT>old = self.real_list[index]<EOL>self.real_list[index] = val<EOL>self.observer(UpdateType.UPDATED, val, index, old=old)<EOL>
See :meth:`list.__setitem__()` method

Calls observer ``self.observer(UpdateType.UPDATED, item, index)``
if ``val != self[index]``