code: public static Double negativeDouble(String value) {
  		Double doubleValue = Validate.isDouble(value);
  		negative(doubleValue);
  		return doubleValue;
  	}
docs: Checks if the given String is a negative double value.<br>
  This method tries to parse a double value and then checks if it is smaller than 0.
  @param value The String value to validate.
  @return The parsed double value
  @throws ParameterException if the given String value cannot be parsed as double or its value is bigger or equal to 0.