docs: public List<String> getRequiresFeature(ArtifactMetadata amd) {
  
          // Now check we have non-null input. I would like to check for valid
          // features
          // but as these may be user created I cannot find any way to do this so
          // it
          // is important there are no typos in the requires feature list TODO ?
          List<String> requiresFeature = new ArrayList<String>();
          String requiresFeatureProp = amd.getProperty(PROP_REQUIRE_FEATURE);
          if (requiresFeatureProp == null) {
              return null;
          }
          if (requiresFeatureProp.equals("")) {
              return requiresFeature;
          } else {
              String[] features = requiresFeatureProp.split("\\,");
              for (String feature : features) {
                  requiresFeature.add(feature.trim());
              }
              return requiresFeature;
          }
      }