code: public String getAttributeString(String attName) {
  	Object o = attributes.get(attName);
  	if (o == null) {
  	    return null;
  	} else {
  	    return (String) o;
  	}	
      }
docs: Get the value for a given attribute.
  
  @param attName the name of the attribute
  @return the attribute value string
  @throws ClassCastException if attribute value is not a String