How to update Associative Array?

[tastyminerals]

Not sure if the `update` method got changed but I am having 
trouble with understanding it now.
I assumed it would work as easy as in Python:) Just do 
`mydic.update(dic)` or `mydic["key"].update(anotherDic)`.

The docs have the following example.

```
class C{}
C[string] aa;

C older;
C newer;
aa.update("a",
{
     newer = new C;
     return newer;
},
(ref C c)
{
     older = c;
     newer = new C;
     return newer;
});
```

This looks pretty scary and confusing to me tbo. Also, why is 
there an example with class and not simple `int[string]`? I just 
need to know how can I update let's say `int[string]` or nested 
`int[string][string]` AA. Should I also initialise and additional 
C classes before calling this method as in the example?

Considering this is the only example in the docs I could find on 
how to update AA, imagine someone from Python world comes and 
sees this. Next thing he does, is close the page and never come 
back to D again :(