### What it does
Checks for nested assignments.

### Why is this bad?
While this is in most cases already a type mismatch,
the result of an assignment being `()` can throw off people coming from languages like python or C,
where such assignments return a copy of the assigned value.

### Example
```
a = b = 42;
```
Use instead:
```
b = 42;
a = b;
```