code: public static <T, K, V> MutableMap<K, V> toMap(
              Iterable<T> iterable,
              Function<? super T, ? extends K> keyFunction,
              Function<? super T, ? extends V> valueFunction)
      {
          return Iterate.addToMap(iterable, keyFunction, valueFunction, UnifiedMap.<K, V>newMap());
      }
docs: Iterate over the specified collection applying the specified Functions to each element to calculate
  a key and value, and return the results as a Map.