code: protected void toStringFields(final StringBuffer buffer) {
  
          buffer.append("<managedConnectionFactory=");
          buffer.append(_managedConnectionFactory);
          buffer.append("> <coreConnection=");
          buffer.append(_coreConnection);
          buffer.append("> <localTransaction=");
          buffer.append(_localTransaction);
          buffer.append("> <xaResource=");
          buffer.append(_xaResource);
          buffer.append("> <metaData=");
          buffer.append(_metaData);
          buffer.append("> <userDetails=");
          buffer.append(_userDetails);
          buffer.append("> <subject=");
          buffer.append(subjectToString(_subject));
          buffer.append("> <logWriter=");
          buffer.append(_logWriter);
          buffer.append("> <sessions=");
          buffer.append(_sessions);
  
          // Don't call toString on listeners as this will result in recursive calls under JBoss and a StackOverFlow
          buffer.append("> <connectionListeners=[");
          for (int i = 0; i < _connectionListeners.size(); i++) {
              Object o = _connectionListeners.get(i);
              if (i > 0)
                  buffer.append(",");
              buffer.append(o.getClass().getName() + "@" + o.hashCode());
          }
          buffer.append("]>");
  
      }
docs: Appends the fields for this object to the given buffer for the
  <code>toString</code> method.
  
  @param buffer
  the buffer to appends the fields to