public static long skip(Reader input, long toSkip) throws IOException {
        if (toSkip < 0) {
            throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
        }
        /*
         * N.B. no need to synchronize this because: - we don't care if the buffer is created multiple times (the data
         * is ignored) - we always use the same size buffer, so if it it is recreated it will still be OK (if the buffer
         * size were variable, we would need to synch. to ensure some other thread did not create a smaller one)
         */
        if (SKIP_CHAR_BUFFER == null) {
            SKIP_CHAR_BUFFER = new char[SKIP_BUFFER_SIZE];
        }
        long remain = toSkip;
        while (remain > 0) {
            long n = input.read(SKIP_CHAR_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
            if (n < 0) { // EOF
                break;
            }
            remain -= n;
        }
        return toSkip - remain;
    }
Skip characters from an input character stream.
This implementation guarantees that it will read as many characters
as possible before giving up; this may not always be the case for
subclasses of {@link Reader}.

@param input  character stream to skip
@param toSkip number of characters to skip.
@return number of characters actually skipped.
@throws IOException              if there is a problem reading the file
@throws IllegalArgumentException if toSkip is negative
@see Reader#skip(long)
@since 2.0
pay-java-common/src/main/java/com/egzosn/pay/common/util/IOUtils.java