code: @BetaApi
    public final Operation deleteInstanceTemplate(
        ProjectGlobalInstanceTemplateName instanceTemplate) {
  
      DeleteInstanceTemplateHttpRequest request =
          DeleteInstanceTemplateHttpRequest.newBuilder()
              .setInstanceTemplate(instanceTemplate == null ? null : instanceTemplate.toString())
              .build();
      return deleteInstanceTemplate(request);
    }
docs: Deletes the specified instance template. Deleting an instance template is permanent and cannot
  be undone. It is not possible to delete templates that are already in use by a managed instance
  group.
  
  <p>Sample code:
  
  <pre><code>
  try (InstanceTemplateClient instanceTemplateClient = InstanceTemplateClient.create()) {
  ProjectGlobalInstanceTemplateName instanceTemplate = ProjectGlobalInstanceTemplateName.of("[PROJECT]", "[INSTANCE_TEMPLATE]");
  Operation response = instanceTemplateClient.deleteInstanceTemplate(instanceTemplate);
  }
  </code></pre>
  
  @param instanceTemplate The name of the instance template to delete.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails