code: public boolean hasAttribute(String key) {
  		if (featindex.containsKey(key)){
  			Map<String, List<FeatureI>> mappa = featindex.get(key);
  			if (mappa!= null && mappa.size()>0)return true;
  			return false;
  		}
  		for (FeatureI f : this) {
  			if (f.hasAttribute(key)) {
  				return true;
  			}
  		}
  
  		return false;
  	}
docs: Check if any feature in list has the specified attribute key.
  
  @param key The attribute key to consider.
  @return True if at least one feature has the attribute key.