Realize a class Dictionary2 to represent dictionaries and having the following
class interface:

public class Dictionary2 {

  // public methods

  // constructs a dictionary that can have an unlimited number of entries
  public Dictionary2() { }

  // searches for word in the dictionary;
  // if word is found, the corresponding definition is returned;
  // otherwise null is returned
  public String search(String word) { }

  // inserts the entry formed by word and definition in the dictionary
  public void insert(String word, String definition) { }
      
  // removes an entry corresponding to word, if it exists,
  // otherwise it does nothing;
  // if there is more than one entry corresponding to word, a randomly chosen
  // one is removed;
  public void remove(String word) { }

  // removes all entries corresponding to word
  // (if theres is no such entry, does nothing);
  public void removeAll(String word) { }

}

Observations:
  - How can we store a number of entries that can grow arbitrarily?