code: public Config getConfig(URI configKeyUri)
        throws ConfigStoreFactoryDoesNotExistsException, ConfigStoreCreationException, VersionDoesNotExistException {
      return getConfig(configKeyUri, Optional.<Config>absent());
    }
docs: Get the resolved {@link Config} based on the input URI.
  
  @param configKeyUri - The URI for the configuration key. There are two types of URI:
  
  1. URI missing authority and configuration store root , for example "etl-hdfs:///datasets/a1/a2". It will get
  the configuration based on the default {@link ConfigStore} in etl-hdfs {@link ConfigStoreFactory}
  2. Complete URI:  for example "etl-hdfs://eat1-nertznn01.grid.linkedin.com:9000/user/mitu/HdfsBasedConfigTest/"
  
  @return  the resolved {@link Config} based on the input URI.
  
  @throws ConfigStoreFactoryDoesNotExistsException: if missing scheme name or the scheme name is invalid
  @throws ConfigStoreCreationException: Specified {@link ConfigStoreFactory} can not create required {@link ConfigStore}
  @throws VersionDoesNotExistException: Required version does not exist anymore ( may get deleted by retention job )