salih ayan wrote: l already wrote class name.which is AssertionTest
Yes, you did, you wrote a class name as part of the -da option. Don't confuse that with the name of the class you want to run, which you still need to state.
Should l add something more after the class name
Yes; more precisely
you should add something after the -da option, which contains a class name. Note that the class name you provide to the -da option isn't necessarily the name of the class you want to run.