code: function getParameterWriterForEventType(eventType) {
      switch (eventType) {
        case EventType.HTTP_TRANSACTION_SEND_REQUEST_HEADERS:
        case EventType.HTTP_TRANSACTION_SEND_TUNNEL_HEADERS:
        case EventType.TYPE_HTTP_CACHE_CALLER_REQUEST_HEADERS:
          return writeParamsForRequestHeaders;
  
        case EventType.PROXY_CONFIG_CHANGED:
          return writeParamsForProxyConfigChanged;
  
        case EventType.CERT_VERIFIER_JOB:
        case EventType.SSL_CERTIFICATES_RECEIVED:
          return writeParamsForCertificates;
        case EventType.CERT_CT_COMPLIANCE_CHECKED:
        case EventType.EV_CERT_CT_COMPLIANCE_CHECKED:
          return writeParamsForCheckedCertificates;
      }
      return null;
    }
docs: Finds a writer to format the parameters for events of type |eventType|.
  
  @return {function} The returned function "writer" can be invoked
  as |writer(entry, writer, consumedParams)|. It will
  output the parameters of |entry| to |out|, and fill
  |consumedParams| with the keys of the parameters
  consumed. If no writer is available for |eventType| then
  returns null.