exteact_async_step.js

var m_secondStep = function m_secondStep(firstStepResult, myFuncParam1) {
  // Both firstStepResult and myFuncParam1 are available
  ...
}

mod.myFunc = function (myFuncParam1, ...) {
  async.waterfall([
    function firstStep() {
      cb(null, firstStepResult)
    },
    // null -> this - ??
    m_secondStep.bind(null, myFuncParam1),
    ...
  ])
}

caolan/async#725