nl_tokens: Flowa
pl_tokens: function Flowa ( flow , name ) { /**
     * A name for the flow
     * @type {String}
     */ this . name = typeof name == 'undefined' ? null : name ; /**
     * The root task
     * @type {Object}
     */ this . _root = flow ; /**
     * Tasks indexed by their names
     * @type {Object}
     */ this . _tasks = { } ; /**
     * Runners types and their handlers
     * @type {Object}
     */ this . _runners = { <mask> : serial , parallel : parallel } ; /**
     * The name of the root task
     * @type {Symbol}
     */ this . _rootName = Symbol ( '__root__' ) ; /**
     * A mapping between tasks names and runners types
     * @type {Object}
     */ this . _tasksRunnersTypes = { } ; /**
     * A mapping between tasks names and their depth
     * @type {Object}
     */ this . _tasksDepths = { } ; /**
     * A mapping between tasks names and their parent task's name
     * @type {Object}
     */ this . _tasksParents = { } ; /**
     * The default runner type
     * @type {String}
     */ this . _defaultRunnerType = 'serial' ; /**
     * Initialize the Flowa object
     */ this . _init ( ) ; }