Actually, I need to get a response of an API call, for that I required Context.
Context
Update.
Just use for version 1.x and 2.x:
Robolectric.application;
And for version 3.x:
RuntimeEnvironment.application;
And for version 4.x:
add to your build.gradle file:
build.gradle
testImplementation 'androidx.test:core:1.0.0'
retrieve the context with:
ApplicationProvider.getApplicationContext()