public String byteCountToDisplaySize( long byteCount ) {
    String spacedDisplaySize = FileUtils.byteCountToDisplaySize( byteCount );
    return spacedDisplaySize.replace( "bytes", "B" ).replace( " ", "" );
  }
@Test
  public void byteCountToDisplaySize() {

    StorageUnitConverter storageUnitConverter = new StorageUnitConverter();

    // TEST 1
    assertEquals( "0B", storageUnitConverter.byteCountToDisplaySize( 0 ) );

    // TEST 2
    assertEquals( "5B", storageUnitConverter.byteCountToDisplaySize( 5 ) );

    // TEST 3
    assertEquals( "13KB", storageUnitConverter.byteCountToDisplaySize( 13 * KB ) );

    // TEST 4
    assertEquals( "13KB", storageUnitConverter.byteCountToDisplaySize( (long) ( 13.1 * KB ) ) );

    // TEST 4
    assertEquals( "128MB", storageUnitConverter.byteCountToDisplaySize( (long) ( 128.9 * MB ) ) );

    // TEST 5
    assertEquals( "6GB", storageUnitConverter.byteCountToDisplaySize( (long) ( 6 * GB ) ) );
  }