The Task Bag is an object that stores (key, value) pairs. A key is a string and a value is a sequence of bytes. Its interface provides the following remote methods

pairOut, with two parameters through which the client specifies a key and a value to be stored.

pairIn, whose first parameter allows the client to specify the key of a pair to be removed from the Task Bag.

The value in the pair is supplied to the client via a second parameter. If no matching pair is available, an exception is thrown.
readPair, which is the same as pairIn except that the pair remains in the Task Bag.

Use CORBA IDL to define the interface of the Task Bag. Define an exception that can be thrown whenever any one of the operations cannot be carried out. Your exception should return an integer indicating the problem number and a string describing the problem. The Task Bag interface should define a single attribute giving the number of tasks in the bag.

Note that sequences must be defined as typedefs. Key is also a typedef for convenience.

```
typedef string Key;
typedef sequence Value;
interface TaskBag {
readonly attribute long numberOfTasks;
exception TaskBagException { long no; string reason; };
void pairOut (in Key key, in Value value) raises (TaskBagException); void pairIn (in Key key, out Value value) raises (TaskBagException); void readPair (in Key key, out Value value) raises (TaskBagException);
};
```