public static byte[] copy(byte[] src, int offset, int length) {
		byte[] copy = new byte[length];
		System.arraycopy(src, offset, copy, 0, length);
		return copy;
	}
public static byte [ ] copy ( byte [ ] src , int offset , int length ) { byte [ ] copy = new byte [ length ] ; System . arraycopy ( src , offset , copy , 0 , length ) ; return copy ; }
Create a new byte array with contents initialized to values from the
argument byte array.
@param src source byte array of initial values
@param offset start offset to copy bytes
@param length number of bytes to copy
@return a new byte array of size length, containing values from src
starting from offset in the src array.