code: def __defer_namespace_export(namespace, symbols)
        @__namespace_exports ||= Hash.new { |h, k| h[k] = [] }
        @__namespace_exports[namespace].concat(symbols)
      end
docs: Defers exporting of symbols for a namespace (nested module), to be
   performed after the entire module has been loaded
   @param namespace [Module] namespace module
   @param symbols [Array] array of symbols
   @return [void]