@java.lang.Override
    public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
      if (authenticationCase_ == 1) {
        output.writeMessage(
            1,
            (com.google.cloud.websecurityscanner.v1.ScanConfig.Authentication.GoogleAccount)
                authentication_);
      }
      if (authenticationCase_ == 2) {
        output.writeMessage(
            2,
            (com.google.cloud.websecurityscanner.v1.ScanConfig.Authentication.CustomAccount)
                authentication_);
      }
      if (authenticationCase_ == 4) {
        output.writeMessage(
            4,
            (com.google.cloud.websecurityscanner.v1.ScanConfig.Authentication.IapCredential)
                authentication_);
      }
      getUnknownFields().writeTo(output);
    }
<pre>
Authentication using Identity-Aware-Proxy (IAP).
</pre>

<code>
.google.cloud.websecurityscanner.v1.ScanConfig.Authentication.IapCredential iap_credential = 4;
</code>
java-websecurityscanner/proto-google-cloud-websecurityscanner-v1/src/main/java/com/google/cloud/websecurityscanner/v1/ScanConfig.java