Alias for trait causes error

[maikgreubel]

In my class an trait alias is defined which causes this error:

     [exec] [25.08.2017 - 13:54:32] Scanning directory 'd:/web/phpGenerics/src' for files to process
     [exec]
     [exec] .........................................f........  [50]
     [exec] ...                                                 [53]
     [exec]
     [exec] [25.08.2017 - 13:54:33] The following file(s) had errors during processing and were excluded:
     [exec] [25.08.2017 - 13:54:33]  - d:/web/phpGenerics/src/Generics/Streams/MemoryStream.php (Referenced trait "" not used [UnitCollectingVisitor.php:213])

This is the code which defines the alias trait:

class MemoryStream implements InputOutputStream
{
    use Interpolator {
        interpolate as tinterpolate;
    }

The alias for trait syntax is pretty correct as shown in documenation (paragraph "Conflict resolution"): http://php.net/manual/en/language.oop5.traits.php