    # File lib/needle/lifecycle/proxy.rb, line 45
          def method_missing( sym, *args, &block )
            unless @instance || @instantiation_failed
              @mutex.synchronize do
                unless @instance || @instantiation_failed
                  begin
                    @instance = @callback.call( *@args )
                  rescue Exception
                    @instantiation_failed = true
                    raise
                  end
                end
              end
            end

            unless @instantiation_failed
              @instance.__send__ sym, *args, &block
            else
              # just return nil... this way, a failed instantiation won't barf
              # more than once... I hope...
            end
          end