var defaultPersistence={ 'NODEJS': 'fs', 'BROWSER': 'localStorage', 'CORDOVA': null }; 

if (this.persistenceMethod == null){
   this.persistenceMethod = defaultPersistence[this.ENV];
   if (! this.persistenceMethod){
     throw Error('unknown environment')
   }
}

if (this.persistenceMethod === 'adapter') {
  if  ( this.persistenceAdapter ) == null;
  throw Error('persistenceAdapter not configured')
}
  
if ( this.persistenceMethod === 'fs') {
   this.persistenceAdapter = new lokiFsAdapter;
}
if this.persistenceMethod === 'localStorage' {
   this.persistenceAdapter = new lokiLocalStorageAdapter;
}