### .simplify_full() doesn't simplify an obvious trigonometric expression

Hello, I'm trying to simplify a trigonometric expression, and it didn't work as I expected. The original example was larger, but I reproduced the issue with a smaller one:

```
sage: y = (sin(x)+2) * sqrt( sin(x) / (sin(x)^2 + 4*sin(x) + 4) )
sage: y.simplify_full()
sqrt(sin(x)/(sin(x)^2 + 4*sin(x) + 4))*(sin(x) + 2)
```

Why doesn't that turn into `sqrt(sin(x))`

? What do I miss?