code: @Override
      public boolean isRedirect()
      {
          FacesContext facesContext = FacesContext.getCurrentInstance();
          boolean thisRedirect = _isRedirectTrueOnThisRequest(facesContext);
          boolean prevRedirect = _isRedirectTrueOnPreviousRequest(facesContext);
          boolean executePhase = !PhaseId.RENDER_RESPONSE.equals(facesContext.getCurrentPhaseId());
          
          return thisRedirect || (executePhase && prevRedirect);
      }
docs: Return the value of this property for the flash for this session.
  
  This must be false unless:
  - setRedirect(boolean) was called for the current lifecycle traversal
  with true as the argument.
  - The current lifecycle traversal for this session is in the "execute"
  phase and the previous traversal had setRedirect(boolean) called with
  true as the argument.