Hey! Can anyone help me achieve result using strea...

# announcements

[Maciej Najbar]

Hey! Can anyone help me achieve result using streams? I use two for-loops to achieve something like this:
List<E> -> Map<K, List<V>>, where E.map<K, V>

Example
Entry:

Element_1
    - Key: Value
Element_2
    - Key: Value

Result in:

Key
    - Value
    - Value

Maybe there is some more efficient way than 12 lines?