nl_tokens: return a cached list of availables adapter unless forceRefresh is true
pl_tokens: function listAvailables ( forceRefresh ) { forceRefresh && ( adaptersCache = [ ] ) ; if ( adaptersCache . <mask> ) { return adaptersCache ; } adaptersCache = fs . readdirSync ( __dirname ) . filter ( function ( fileOrDirName ) { return isDir ( __dirname + '/' + fileOrDirName ) ; } ) ; return adaptersCache ; }