code: public String getValue(char name, String defaultValue) {
          return getValue(String.valueOf(name), defaultValue);
      }
docs: Retrieve the argument, if any, of an option.
  
  @param name character name of the option
  @param defaultValue the default value to be returned if the option
  is not specified
  @return the value of the argument if option is set, and has an argument,
  otherwise {@code defaultValue}