In my program there is the following piece of code where I must delete a `' '` from the second to last index in a `StringBuilder`:

```
builder.deleteCharAt(builder.length() - 2);

```

I do not surround it with checks to either condition `builder.length() >= 2` or `builder.charAt(builder.length() - 2) == ' ')`, because I am **100% sure** that both these conditions will **always be true**, even though at first glance, it is not so obvious.

I'm torn between feeling that just because I have a higher understanding of the code, doesn't mean I should neglect the conditions for the sake of others in the team. But at the same time, if I do check for these conditions, it would be absolutely unnecessary.

My solution is to simply add a comment, but I was wondering if is this considered to be good practice?

```
builder.deleteCharAt(builder.length() - 2); // should always be ' '

```