Objects.requireNonNull(size, "size");
        final String displaySize;

        if (size.divide(ONE_EB_BI).compareTo(BigInteger.ZERO) > 0) {
            displaySize = new BigDecimal(size.divide(ONE_PB_BI)).divide(BigDecimal.valueOf(1000)) + "EB";
        } else if (size.divide(ONE_PB_BI).compareTo(BigInteger.ZERO) > 0) {

        assertEquals("909.494PB", MemoryUtil.byteCountToDisplaySize(1000_000_000_000_000_000L));
        assertEquals("1.024EB", MemoryUtil.byteCountToDisplaySize(FileUtils.ONE_EB));
    }

    public void test_getUsedMemory() {
        assertTrue(MemoryUtil.getUsedMemory() >= 0);
    }

    public void test_sizeOf() throws Exception {