code: public static MemorySize parse(String text, MemoryUnit defaultUnit) throws IllegalArgumentException {
  		if (!hasUnit(text)) {
  			return parse(text + defaultUnit.getUnits()[0]);
  		}
  
  		return parse(text);
  	}
docs: Parses the given string with a default unit.
  
  @param text The string to parse.
  @param defaultUnit specify the default unit.
  @return The parsed MemorySize.
  
  @throws IllegalArgumentException Thrown, if the expression cannot be parsed.