Behat could not load mock class already exists

Question

I am trying to mock a class in Laravel using the following. However, I get the following error. Any ideas?

Could not load mock \App\Repositories\FetchDataEndpoints\Test, class already exists.

\Mockery::mock('overload:\App\Repositories\FetchDataEndpoints\Test')
    ->shouldReceive([
        'getPaymentStatus' => 'test'
]);