Assign coveredText of a FSArray Annotation to a string Feature

Question

Working with FSArray Annotations within UIMA Ruta, I need to extract an annotation's coveredText and store it into a string feature of a different annotation.

As suggested in the documentation, I tried using the GET action in the following way:

ANNOTATION tempAnno;
a:Anno {-> GET(a.items, tempAnno, "dominant"), CREATE(SimpleAnno, "stringFeat"=tempAnno.ct)};

but it didn't produce the expected outcome, as the SimpleAnno.stringFeat is null.

What would be the best way to achieve this?