Question: chain.Unwrap behaviour

chain.Unwrap() has a test to see whether the end of the chain has been reached. I don't understand this; is it correct?

*multierror.go:*
```go
// Unwrap implements errors.Unwrap by returning the next error in the
// chain or nil if there are no more errors.
func (e chain) Unwrap() error {
if len(e) == 1 { // line 106
return nil
}

return e[1:]
}
```

It seems to me that line 106 might have a mistake and should be ` if len(e) < 1 {`.

Have I misunderstood this?

I am using v1.1.1.