code: public String getSingleProp(Prop.Names prop) throws CommandExecutionException {
          Map<Prop.Names, String> value = getProps(new Prop.Names[]{prop});
          String valueString = value.get(prop);
          if (valueString == null) throw new CommandExecutionException(CommandExecutionException.Error.INVALID_RESPONSE);
          return valueString;
      }
docs: Get a single property value from the device.
  @param prop The property to get.
  @return The value of the specified property name.
  @throws CommandExecutionException When there has been a error during the communication or the response was invalid.