enum ScaleUnit {
            BYTE {
                @Override
                public long bytes() {
                    return 1L;
                }

                @Override
                public String symbol() {
                    return "B";
                }
            },
            KILOBYTE {
                @Override
                public long bytes() {
                    return 1000L;
                }

                @Override
                public String symbol() {
                    return "kB";
                }
            },
            MEGABYTE {
                @Override
                public long bytes() {
                    return KILOBYTE.bytes() * KILOBYTE.bytes();
                }

                @Override
                public String symbol() {
                    return "MB";
                }
            },
            GIGABYTE {
                @Override
                public long bytes() {
                    return MEGABYTE.bytes() * KILOBYTE.bytes();
                }
                ;

                @Override
                public String symbol() {
                    return "GB";
                }
            };

            public abstract long bytes();

            public abstract String symbol();

            public static ScaleUnit getScaleUnit(long size) {
                if (size < 0L) {
                    throw new IllegalArgumentException("file size cannot be negative: " + size);
                }

                if (size >= GIGABYTE.bytes()) {
                    return GIGABYTE;
                } else if (size >= MEGABYTE.bytes()) {
                    return MEGABYTE;
                } else if (size >= KILOBYTE.bytes()) {
                    return KILOBYTE;
                } else {
                    return BYTE;
                }
            }
        }