public:
void init(const std::vector<double> &bucket_vals);
void init_uniform(size_t num_buckets); // Sets up buckets 0..(N-1).
+ void init_geometric(double min, double max, size_t num_buckets);
void count_event(double val);
std::string serialize(const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels) const;