def has_service?(service_name)

      service_name = service_name.to_s
      service_name = "s_#{service_name}" if ! SERVICE_PREFIX.match(service_name)

      @services.has_key?(service_name)
    end
def has_service?(service_name)

      service_name = service_name.to_s
      service_name = "s_#{service_name}" if ! SERVICE_PREFIX.match(service_name)

      @services.has_key?(service_name)
    end
Returns true if this context has a given service registered.