How to use org.janusgraph.diskstorage.configuration

@Override
public boolean has(ConfigOption option, String... umbrellaElements) {
  verifyOption(option);
  return config.get(super.getPath(option,umbrellaElements),option.getDatatype())!=null;
}

@Override
public <O> O get(ConfigOption<O> option, String... umbrellaElements) {
  if (option.getNamespace().hasUmbrella())
    return config.get(option,concat(umbrellaElements));
  else
    return config.get(option);
}

@Override
public boolean has(ConfigOption option, String... umbrellaElements) {
  if (option.getNamespace().hasUmbrella())
    return config.has(option,concat(umbrellaElements));
  else
    return config.has(option);
}

@Override
public <O> O get(ConfigOption<O> option, String... umbrellaElements) {
  if (first.has(option, umbrellaElements))
    return first.get(option, umbrellaElements);
  if (second.has(option, umbrellaElements))
    return second.get(option, umbrellaElements);
  return option.getDefaultValue();
}
@Override

public<O> ModifiableConfiguration set(ConfigOption<O> option, O value, String... umbrellaElements) {
  verifyOption(option);
  Preconditions.checkArgument(hasUpgradeableFixed(option.getName()) ||
                !option.isFixed() || !isFrozen(), "Cannot change configuration option: %s", option);
  String key = super.getPath(option,umbrellaElements);
  value = option.verify(value);
  config.set(key,value);
  return this;
}

@Override
public boolean has(ConfigOption option, String... umbrellaElements) {
  final String key = super.getPath(option, umbrellaElements);
  return option.isLocal() && local.get(key, option.getDatatype()) != null
     || option.isGlobal() && global.get(key, option.getDatatype()) != null;
}

public AbstractStoreManager(Configuration storageConfig) {
  batchLoading = storageConfig.get(STORAGE_BATCH);
  boolean transactional = storageConfig.get(STORAGE_TRANSACTIONAL);
  if (batchLoading) {
    transactional = false;
  }
  this.transactional = transactional;
  this.storageConfig = storageConfig;
}

protected String getPath(ConfigElement option, String... umbrellaElements) {
  verifyElement(option);
  return ConfigElement.getPath(option,umbrellaElements);
}

@Override
public Map<String, Object> getSubset(ConfigNamespace umbrella, String... umbrellaElements) {
  return config.getSubset(umbrella,concat(umbrellaElements));
}

public<O> void remove(ConfigOption<O> option, String... umbrellaElements) {
  verifyOption(option);
  Preconditions.checkArgument(!option.isFixed() || !isFrozen(), "Cannot change configuration option: %s", option);
  String key = super.getPath(option,umbrellaElements);
  config.remove(key);
}

public void freezeConfiguration() {
  config.set(FROZEN_KEY, Boolean.TRUE);
  if (!isFrozen()) setFrozen();
}

public Configuration getConfig() {
  return new BasicConfiguration(GraphDatabaseConfiguration.ROOT_NS, config.copy(), BasicConfiguration.Restriction.NONE);
}

@Override
public Set<String> getContainedNamespaces(ConfigNamespace umbrella, String... umbrellaElements) {
  return config.getContainedNamespaces(umbrella,concat(umbrellaElements));
}

public ConfigNamespace getRoot() {
  if (isRoot()) return (ConfigNamespace)this;
  else return getNamespace().getRoot();
}

public Builder(KeyColumnValueStore store, StoreManager manager) {
  this.store = store;
  this.manager = manager;
  this.lockWait = GraphDatabaseConfiguration.LOCK_WAIT.getDefaultValue();
  this.lockRetryCount = GraphDatabaseConfiguration.LOCK_RETRY.getDefaultValue();
}

  @Override
  public Configuration restrictTo(String... umbrellaElements) {
    return new MergedConfiguration(first.restrictTo(umbrellaElements), second.restrictTo(umbrellaElements));
  }
}

  @Override
  public Configuration restrictTo(String... umbrellaElements) {
    return config.restrictTo(concat(umbrellaElements));
  }
};

/**
 * Returns the backing configuration as a {@link ReadConfiguration} that can be used
 * to create and configure a JanusGraph graph.
 *
 * @return
 */
public ReadConfiguration getConfiguration() {
  return config.getConfiguration();
}

@Override
public<O> O get(ConfigOption<O> option, String... umbrellaElements) {
  final String key = super.getPath(option,umbrellaElements);
  Object result = null;
  if (option.isLocal()) {
    result = local.get(key,option.getDatatype());
  }
  if (result==null && option.isGlobal()) {
    result = global.get(key,option.getDatatype());
  }
  return option.get(result);
}

@Override
public<O> O get(ConfigOption<O> option, String... umbrellaElements) {
  verifyOption(option);
  O result = config.get(super.getPath(option,umbrellaElements),option.getDatatype());
  return option.get(result);
}