nl_tokens: add all features in the given hash or array
pl_tokens: function ( hash ) { if ( <mask> instanceof Array ) { for ( var index in hash ) this . addFeature ( hash [ index ] ) ; } else if ( hash instanceof Object ) { for ( var feature in hash ) this . addFeature ( feature ) ; } else throw new Error ( "FeatureLookupTable.addFeatures expects a hash or an array, but got: " + JSON . stringify ( hash ) ) ; }