This object is used to calculate the accuracy of the model in the
fitting process. This object is used internally inside a luz workflow.
Details
This function is a generator created using luz::luz_metric() function.
It has a initialize() method that sets the total number of instances
and total number of correct predictions as zero. For any mini batch, it
has an update() method that updates the total number of instances and
total number of correct predictions with new data. Finally, it has a
compute() method that calculates accuracy from the total number of
correct predictions and total number of instances.