@Test
public void testCanSendHeaders() throws IOException {

  ByteArrayOutputStream baos = new ByteArrayOutputStream();
  ThruStagingHandler handler = new ThruStagingHandler( baos, session );
  assertTrue( handler.canSendHeaders() );
  handler.getStagingOutputStream().write( TEST.getBytes() );
  assertFalse( "Can't send headers after start writing to THRU", handler.canSendHeaders() );
}