code: public static final void merge(InputStream in1, InputStream in2, OutputStream out, boolean closeIS1, boolean closeIS2, boolean closeOS) throws IOException {
  	try {
  	    merge(in1, in2, out, 0xffff);
  	}
  	finally {
  	    if (closeIS1) closeEL(in1);
  	    if (closeIS2) closeEL(in2);
  	    if (closeOS) closeEL(out);
  	}
      }
docs: copy a inputstream to a outputstream
  
  @param in
  @param out
  @param closeIS
  @param closeOS
  @throws IOException