Activity Chart Checks : (C4135) Elements that flow from/to router without a matching flow in descendant chart

(C4135) Elements that flow from/to router without a matching flow in descendant chart

Error In:
Completeness
Description:
There are elements that flow from or to the router without matching flow-lines in descendant charts lower in the hierarchy.
Note that this test avoids warnings for empty information-flows. (This behavior is consistent with Check-Model tests C4058 and C4059.)
Example:
Consider the example in the following figure - Tested Activity-chart: TOP1
(C4135) Elements that flow from/to router without a matching flow in descendent chart:

Y flows to @AC_2 through ROUTER_1 from AC3

W flows from @AC_2 through ROUTER_1 to AC3

Erroneous Elements:
Events, conditions, data-items, information-flows, and fields