code: @Test public void testInvalidConstructorInput() throws Exception {
    try {
      new HttpResponseParser(null,BasicLineParser.DEFAULT,new DefaultHttpResponseFactory(),new BasicHttpParams());
      Assert.fail("IllegalArgumentException should have been thrown");
    }
   catch (  IllegalArgumentException ex) {
    }
    try {
      SessionInputBuffer inbuffer=new SessionInputBufferMock(new byte[]{});
      new HttpResponseParser(inbuffer,BasicLineParser.DEFAULT,null,new BasicHttpParams());
      Assert.fail("IllegalArgumentException should have been thrown");
    }
   catch (  IllegalArgumentException ex) {
    }
    try {
      SessionInputBuffer inbuffer=new SessionInputBufferMock(new byte[]{});
      new HttpResponseParser(inbuffer,BasicLineParser.DEFAULT,new DefaultHttpResponseFactory(),null);
      Assert.fail("IllegalArgumentException should have been thrown");
    }
   catch (  IllegalArgumentException ex) {
    }
  }
  