code: public Configuration removeConfiguration(String name)
      {
          Configuration conf = getConfiguration(name);
          if (conf != null && !conf.equals(containerConfiguration))
          {
              configList.remove(conf);
              namedConfigurations.remove(name);
          } else if (conf != null && conf.equals(containerConfiguration)) {
              throw new IllegalArgumentException("Can't remove container configuration");
          }
          return conf;
      }
docs: Removes the configuration with the specified name.
  
  @param name the name of the configuration to be removed
  @return the removed configuration (<b>null</b> if this configuration
  was not found)