code: public boolean checkExpiration(boolean updateAccessTime) {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEventEnabled()) {
              Tr.event(tc, "checkExpiration: " + this);
          }
          if (isInvalid()) {
              // we're marked invalid already
              return true;
          }
          long now = System.currentTimeMillis();
          if ((NO_TIMEOUT == this.maxInactiveTime)
              || (this.maxInactiveTime > (now - this.lastAccesss))) {
              // still valid session
              if (updateAccessTime) {
                  this.isNew = false;
                  this.lastAccesss = now;
              }
              return false;
          }
          return true;
      }
docs: Check for possible expiration of this existing session. This will
  update the last access time if still valid, and changes the isNew
  flag to false if not already (since we now know the client has
  re-used the session information). This will return true if the
  session is expired or false if still valid. The caller should
  start the invalidation process if this returned true.
  
  @param updateAccessTime
  @return boolean