code: public void setAttribute(String name, Object attribute) {
          if (!_iSess.isValid())
              throw new IllegalStateException();
          if (null != attribute) {
              if (!(attribute instanceof HttpSessionBindingListener)) {
                  _iSess.setAttribute(name, attribute, Boolean.FALSE);
              } else {
                  _iSess.setAttribute(name, attribute, Boolean.TRUE);
              }
          } else {
              // attribute is null
              // if name is not null, remove it ... otherwise do nothing
              if (name != null) {
                  _iSess.removeAttribute(name);
              }
          }
      }
docs: /*
  (non-Javadoc)
  
  @see
  com.ibm.websphere.servlet.session.IBMApplicationSession#setAttribute(java
  .lang.String, java.lang.Object)