nl_tokens: Deeply iterates over the keys of an object to remove any keys that are undefined . This method modifies the object .
pl_tokens: function deepRemoveUndefinedKeysFromObject ( obj ) { for ( let key in obj ) { if ( obj . hasOwnProperty ( key ) ) { if ( _ . isUndefined ( obj [ key ] ) ) { delete obj [ key ] ; } else if ( _ . isObject ( obj [ <mask> ] ) ) { deepRemoveUndefinedKeysFromObject ( obj [ key ] ) ; } } } return obj ; }