When using the generator with the script format :
generator-name [params] > test-index
eg : gen_rnd 1 100 0 1000 > 1
The test case files get generated.
But when using script format to generate multiple files :
generator-name [params] > {test-indices}
eg : gen_rnd 1 100 0 1000 > {1-2}
The test case file show an error :
ERROR