public static byte[] copy(byte[] bytes){
  if (bytes == null)   return null;
  byte[] result=new byte[bytes.length];
  System.arraycopy(bytes,0,result,0,bytes.length);
  return result;
}

public static byte [ ] copy ( byte [ ] bytes ) { if ( bytes == null ) return null ; byte [ ] result = new byte [ bytes . length ] ; System . arraycopy ( bytes , 0 , result , 0 , bytes . length ) ; return result ; }
copy the byte array given in parameter and return an instance of a new byte array with the same length and the same content .
