code: private void setAnnotationRole(Attributes attributes, BugAnnotation bugAnnotation) {
          String role = getOptionalAttribute(attributes, "role");
          if (role != null) {
              bugAnnotation.setDescription(role);
          }
      }
docs: /*
  Extract a hash value from an element.
  
  @param qName
  name of element containing hash value
  @param attributes
  element attributes
  @return the decoded hash value
  @throws SAXException
  
  private byte[] extractHash(String qName, Attributes attributes) throws SAXException {
  String encodedHash = getRequiredAttribute(attributes, "value", qName);
  byte[] hash;
  try {
  System.out.println("Extract hash " + encodedHash);
  hash = ClassHash.stringToHash(encodedHash);
  } catch (IllegalArgumentException e) {
  throw new SAXException("Invalid class hash", e);
  }
  return hash;
  }