docs: function MarkovChainStateEngine(converter, entities) {
    MarkovChainStateEngine.super_.call(this, converter);
  
    this.converter = converter;
    this.initializedForTransition = false;
    this.transitionCountTotals = {};
    this.transitions = {};
    this.transitionDefinitions = {};
  
    // Add whatever entities we've been provided.
    var self = this;
    if (entities) {
      entities.forEach(function(element) {
        self.addDefiningEntity(element);
      });
    }
  }