code: public static Double isDouble(String value) {
  		Validate.notNull(value);
  		Validate.notEmpty(value);
  		Double doubleValue = null;
  		try{
  			doubleValue = Double.parseDouble(value);
  		} catch(NumberFormatException e){
  			throw new TypeException("Double");
  		}
  		return doubleValue;
  	}
docs: Checks if the given String is a double value.
  @param value The String value to validate.
  @return The parsed double value.
  @throws ParameterException if the given String value cannot be parsed as double.