code: private static long parse(final String argument) throws NumberFormatException {
  		if (argument.endsWith("gb")) {
  			return Long.parseLong(argument.substring(0, argument.length() - "gb".length()).trim()) * GB;
  		} else if (argument.endsWith("mb")) {
  			return Long.parseLong(argument.substring(0, argument.length() - "mb".length()).trim()) * MB;
  		} else if (argument.endsWith("kb")) {
  			return Long.parseLong(argument.substring(0, argument.length() - "kb".length()).trim()) * KB;
  		} else if (argument.endsWith("bytes")) {
  			return Long.parseLong(argument.substring(0, argument.length() - "bytes".length()).trim());
  		} else {
  			return Long.parseLong(argument.trim());
  		}
  	}
docs: Parses file size from a string. The units GB, MB, KB and bytes are supported.
  
  @param argument
  Lower case file size
  @return Parsed file size
  @throws NumberFormatException
  Failed to parse file size