public static void putDouble(byte[] arr,long off,double val){
  if (UNALIGNED)   UNSAFE.putDouble(arr,off,val);
 else   putLongByByte(arr,off,Double.doubleToLongBits(val),BIG_ENDIAN);
}

public static void putDouble ( byte [ ] arr , long off , double val ) { if ( UNALIGNED ) UNSAFE . putDouble ( arr , off , val ) ; else putLongByByte ( arr , off , Double . doubleToLongBits ( val ) , BIG_ENDIAN ) ; }
stores double value into byte array . alignment aware .
