//compute total event count;
const counts = _.reduce(events, (c, e) => {
  const { event } = e;

  //Remove invalid characters from Name
  const eventName = event.toLowerCase().replace(/\.\$/, '');

  //Fetch or initialize the counter increment
  const operation = c[eventName] || { value: 1, operation: 'inc' };

  //Increment Counter for this event name
  operation.value++;
  c[eventName] = operation;
  return c;
}, {});

/*
  counts == {
    "viewed page": { operation: 'inc', value: 2},
    "email open": { operation: 'inc', value: 2},
    ...
  }
*/

//Write in Hull Profile, in `event_counts` group;
hull.traits(counts, { source: 'event_counts' });