code: public void removeValue(V value) {
          if (value == null) {
              throw new IllegalArgumentException("Method argument value must not be null.");
          }
          for (Collection<V> values : values()) {
              values.remove(value);
          }
      }
docs: Removes the given value from all collections stored under any key.
  
  @param value must not be <code>null</code>.