public Builder clearIapCredential() {
        if (iapCredentialBuilder_ == null) {
          if (authenticationCase_ == 4) {
            authenticationCase_ = 0;
            authentication_ = null;
            onChanged();
          }
        } else {
          if (authenticationCase_ == 4) {
            authenticationCase_ = 0;
            authentication_ = null;
          }
          iapCredentialBuilder_.clear();
        }
        return this;
      }
<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