Method put

src/main/java/com/rtg/util/MultiMap.java:111–113

Adds an empty collection if it does not already exist for the given key. @param key the key to ensure an entry for.

(final K key)

   * @param key the key to ensure an entry for.
   */
  public void put(final K key) {
    putBase(key);
  }

  /**
   * Adds value to collection held by key