Dictionary (ADT)

A dictionary typically implements the methods:

• get(k): if the dictionary $D$ has an entry with key $k$, return it otherwise null
• getAll(k): returns an iterable collection of all entries with key $k$
• put(k,v): inserts into the dictionary $D$ and returns entry $(k,v)$
• remove(e): removes the entry $e$ from the dictionary and returns the removed entry; an error occurs if entry is not in the dictionary $D$
• entrySet(): returns an iterable collection of the entries in the dictionary
• Additional methods: size(), isEmpty().