code: private String getInternal(String key) {
  		Preconditions.checkArgument(configuredOptions.containsKey(key),
  			"The configuration " + key + " has not been configured.");
  
  		return configuredOptions.get(key);
  	}
docs: Returns the value in string format with the given key.
  
  @param key The configuration-key to query in string format.