code: public static String formatUsedMemory() {
  		Runtime runtime = Runtime.getRuntime();
  		long usedMemory = Math.max(0, runtime.totalMemory() - runtime.freeMemory());
  
  		return MemoryUnitFormat.getMemoryUnitInstance().format(usedMemory);
  	}
docs: Formats the currently used memory in human readable format.
  
  @return the currently used memory in human readable format.