The format string '{a|b|c}' will now try to use the value from 'a' and
fall back to 'b' and 'c' if accessing a field raises an exception or
if its value is None.
The format string '{a|b|c}' will now try to use the value from 'a' and
fall back to 'b' and 'c' if accessing a field raises an exception or
if its value is None.