Return the number of occurrences of value in o, that is,
return the number of keys for which o[key] ==
value. On failure, return -1. This is equivalent to
the Python expression "o.count(value)".
Determine if o contains value. If an item in o is
equal to value, return 1, otherwise return 0. On
error, return -1. This is equivalent to the Python expression
"value in o".