public static long toLong(final byte[] bytes, final ByteOrder byteOrder) {
        return toLong(bytes, 0, byteOrder);
    }
Extracts an eight-byte long integer from the specified byte array. This method assumes that the byte array is of sufficiently large size to encode a long
integer.

@param bytes     an array of size at least 8
@param byteOrder the byte-order for interpreting the input bytes
@return an eight-byte signed integer
src/main/java/org/apache/commons/imaging/common/ByteConversions.java