pub fn add(&mut self, activity: &Activity) {
        self.reps_by_category
            .entry(activity.category.to_string())
            .and_modify(|e| *e += activity.reps)
            .or_insert(activity.reps);
    }
/// Add the given activity to the reps in this day
Add the given activity to the reps in this day
Add the given activity to the reps in this day
pub fn add(&mut self, activity: &Activity) {
        self.reps_by_category
            .entry(activity.category.to_string())
            .and_modify(|e| *e += activity.reps)
            .or_insert(activity.reps);
    }
pub fn add ( & mut self , activity : & Activity ) { self . reps_by_category . entry ( activity . category . to_string ( ) ) . and_modify ( | e | * e += activity . reps ) . or_insert ( activity . reps ) ; }
Add the given activity to the reps in this day
Add the given activity to the reps in this day
&mut self
activity
&Activity