javascript - Triggering simultaneous transitions with D3 -

i have built d3 script (click here jsfiddle) connects nodes paths. can see fiddle, have created transition sends circle node node c.

i want amend script follows:

1. send 10 blue/red circles b in 10 seconds
2. send 15 blue/red circles c in 10 seconds
3. steps (1) , (2) simultaneous
4. circle dispatch 'random'. circle speed not vary dispatch triggered unevenly across different paths, color , 10 seconds. more 1 circle can on path @ once.

steps 1 4 can of course saved in array, so:

{   "pathab": {     "duration": 1000,     "blue": 5,     "red":5   },   "pathac": {     "duration": 1000,     "blue": 5,     "red":10   } } 

i stuck. @ moment can't fire 2 sequential events (the second overrides first, , first not triggered). efforts fire simultaneous events failed. have been scanning stack overflow evening limited success. appreciated!