class Datadog::Tracing::Sampling::RateByServiceSampler

def update(rate_by_service, decision: nil)
  # Remove any old services
  delete_if { |key, _| key != DEFAULT_KEY && !rate_by_service.key?(key) }
  # Update each service rate
  update_all(rate_by_service, decision: decision)
  # Emit metric for service cache size
  Datadog.health_metrics.sampling_service_cache_length(length)
end