Event Processor unit testing

Hi, 

I m trying to write unit test for my eventprocessor but I dont know how to moc context object. Any suggestions. This is openasync method I m testing

 public Task OpenAsync(PartitionContext context)
        {
            _log.LogInformation("Opening Event Processor at {ConsumerGroup}-{Partition}",
                context.ConsumerGroupName,
                context.PartitionId);
            return Task.CompletedTask;
        }