code: @SuppressWarnings("unchecked")
      public Collection<TextAnnotation> getTextAnnotations() {
          Collection<? extends Enhancement> result = enhancements
                  .get(TextAnnotation.class);
          return result == null ? Collections.<TextAnnotation>emptySet() : 
              Collections.unmodifiableCollection((Collection<TextAnnotation>) result);
      }
docs: Returns the {@link Collection} of extracted {@link TextAnnotation}s
  
  @return