How to run more than two Instrumentation Runner in gradle project

I need to run two Instrumentation Runner simultaneously one after another. My Instrumentation runner in gradle file is:
if(project.hasProperty(‘Imp’)){
testInstrumentationRunner"android.support.test.runner.AndroidJUnitRunner"
}
else{
testApplicationId"com.android.imp"
testInstrumentationRunner"com.android.imp.Instrumentation"
}
currently i am giving the command to run is
gradle connectedTest -PImp

but the above command run only one instrumentation runner which has the Parameter as “Imp”

so please guide me that how i can run both the runner simultaenously.