set_first_party
  
  Description:
  public void set_first_party (
Uri first_party)
  
 
  
    Sets first_party as the main document Uri for this
      .
    For details of when and how this is used refer to the documentation for [enum@CookieJarAcceptPolicy].
    Parameters:
    
      
        | this | a Message | 
      
        | first_party | the Uri for the this's first party |