code: function wait(msec) {
      return waitTask;
  
      function waitTask(value) {
        var that = this;
        return new promisen.Promise(function(resolve) {
          setTimeout(function() {
            resolve.call(that, value);
          }, msec);
        });
      }
    }
docs: creates a promise-returning function which does just sleep for given milliseconds.
  
  @class promisen
  @static
  @function wait
  @param msec {Number}
  @returns {Function} promise-returning function
  @example
  var promisen = require("promisen");
  
  var sleep = promisen.wait(1000); // 1 sec
  sleep(value).then(function(value) {...});
  
  // similar to below
  setTimeout(function() {...}, 1000);