code: function registerHook(className, hookType, hookFn) {
    if (!hooks[className]) {
      hooks[className] = {};
    }
  
    hooks[className][hookType] = hookFn;
  }
docs: Registers a hook on a class denoted by className.
  
  @param {string} className The name of the class to register hook on.
  @param {string} hookType One of 'beforeSave', 'afterSave', 'beforeDelete', 'afterDelete'
  @param {function} hookFn Function that will be called with `this` bound to hydrated model.
  Must return a promise.
  
  @note Only supports beforeSave, beforeDelete, and afterSave at the moment.