def active_pool_manager
      manager = pool_manager
      unless manager.is_a?(AutoNetwork::PoolManager)
        raise InvalidSettingErrror,
          :setting_name => 'pool_manager',
          :value => manager.inspect
      end

      manager
    end
def active_pool_manager
      manager = pool_manager
      unless manager.is_a?(AutoNetwork::PoolManager)
        raise InvalidSettingErrror,
          :setting_name => 'pool_manager',
          :value => manager.inspect
      end

      manager
    end
Assertively retrieve the global {AutoNetwork::PoolManager} instance.

 Raises an error if {#pool_manager} has been set to `nil` or an invalid
 value.

 @return [AutoNetwork::PoolManager]
 @raise [InvalidSettingErrror] If {#pool_manager} is not set to a usable
   value.