private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.memorystore.v1.MaintenancePolicy,
            com.google.cloud.memorystore.v1.MaintenancePolicy.Builder,
            com.google.cloud.memorystore.v1.MaintenancePolicyOrBuilder>
        getMaintenancePolicyFieldBuilder() {
      if (maintenancePolicyBuilder_ == null) {
        maintenancePolicyBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.memorystore.v1.MaintenancePolicy,
                com.google.cloud.memorystore.v1.MaintenancePolicy.Builder,
                com.google.cloud.memorystore.v1.MaintenancePolicyOrBuilder>(
                getMaintenancePolicy(), getParentForChildren(), isClean());
        maintenancePolicy_ = null;
      }
      return maintenancePolicyBuilder_;
    }
<pre>
Optional. The maintenance policy for the instance. If not provided,
the maintenance event will be performed based on Memorystore
internal rollout schedule.
</pre>

<code>
.google.cloud.memorystore.v1.MaintenancePolicy maintenance_policy = 31 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-valkey/proto-google-cloud-valkey-v1/src/main/java/com/google/cloud/memorystore/v1/Instance.java