| 12345678910111213141516171819 | #pragma once#include <iosfwd>#include <string>#include <vector>#include "prometheus/metric_family.h"namespace prometheus {class Serializer { public:  virtual ~Serializer() = default;  virtual std::string Serialize(const std::vector<MetricFamily>&) const;  virtual void Serialize(std::ostream& out,                         const std::vector<MetricFamily>& metrics) const = 0;};}  // namespace prometheus
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