```
("A", "1");    ("B", "2");    ("C", "2");    ("D", "3");    ("E", "3");    

```

I have a map with duplicate values like above 

I would like to the map to have

```
("A", "1");

```

And in case of list

if list contains `{1,2,2,3,3,4,5}`

i want `{1,4,5}`