code: private boolean getBooleanAttributeValue(Node source) {
          Attr attribute = (Attr)source;
          String value = attribute.getValue();
          return "true".equalsIgnoreCase(value);
      }
docs: Gets the value of an attribute and returns true if it is set to "true"
  (case-insensitive), otherwise returns false.
  
  @param source An Attribute node from the spring configuration
  
  @return boolean