code: @Test public void testContextInvalidInput() throws Exception {
    HttpContext currentContext=new SyncBasicHttpContext(null);
    try {
      currentContext.setAttribute(null,null);
      Assert.fail("IllegalArgumentException should have been thrown");
    }
   catch (  IllegalArgumentException ex) {
    }
    try {
      currentContext.getAttribute(null);
      Assert.fail("IllegalArgumentException should have been thrown");
    }
   catch (  IllegalArgumentException ex) {
    }
    try {
      currentContext.removeAttribute(null);
      Assert.fail("IllegalArgumentException should have been thrown");
    }
   catch (  IllegalArgumentException ex) {
    }
  }
  