code: public static Configuration merge(final Iterable<Configuration> configurations) {
      final ConfigurationBuilder configurationBuilder = Tang.Factory.getTang().newConfigurationBuilder();
      for (final Configuration configuration : configurations) {
        configurationBuilder.addConfiguration(configuration);
      }
      return configurationBuilder.build();
    }
docs: Merge a set of Configurations.
  
  @param configurations the configuration to be merged
  @return the merged configuration.
  @throws org.apache.reef.tang.exceptions.BindException if the merge fails.