public static byte[] flip(final byte[] data, final int index) {
		return get(data, index) ? unset(data, index) : set(data, index);
	}
Flip the bit at the given index.

@param data the data array.
@param index the index of the bit to flip.
@return the input array, for command chaining
@throws IndexOutOfBoundsException if the index is
         {@code index >= max || index < 0}.
@throws NullPointerException if the {@code data} array is {@code null}.
jenetics/src/main/java/io/jenetics/internal/util/Bits.java