With simpler dictionaries like this `Dictionary<key,value>` I know I can add an item to the dictionary like this:

```
if(!myDic.ContainKeys(key))
  myDic[key] = value;

```

But how about a more complex dictionary like this:

```
Dictionary myDic<string, List<MyClass>>

```

where each key might have a list of values of my class? How do we add to that?