I used `strings.Trim()` in Golang to trim the first five characters.  

However, the last "a" is always gone.  

Why is that so? 

Example: 

```
sentence := "Kab. Kolaka Utara"
result := strings.Trim(sentence,sentence[:4])
fmt.Println(result)

```

Result: `Kolaka Utar`  

I expected: `Kolaka Utara`

<https://play.golang.org/p/R6UoKWNaVv>

Thank you for your help.