       args.push outCallback
       outCallback = ()->
 
+    debug '_flow arity = ', args.length
+    debug '_flow err= ', err
     runFlow flowFns, err, args, outCallback
 
 



runFlow = (fnFlows, err, args, outCallback)->
  debug 'runFlow', arguments    

  if err
    errorHandlerArity = args.length + 2 # include err, callback
    fnFlows = cutFlowsByArity(fnFlows, errorHandlerArity)    
 
  return outCallback err, args... if fnFlows.length is 0 

  return (args..., outCallback)->  
    first = args[0]
    err = null
    # debug 'first', first
    if first is null or first is undefined or _isError first
      err = args.shift()
      debug 'set err = ', err
