whole_func_string: function Metric(key, tags, host) {
      this.key = key;
      this.tags = tags || [];
      this.host = host || '';
  }
func_code_string: function Metric(key, tags, host) {
      this.key = key;
      this.tags = tags || [];
      this.host = host || '';
  }
func_documentation_string: --- Metric (base class)