public Builder mergeManagedBackupSource(
        com.google.cloud.memorystore.v1.Instance.ManagedBackupSource value) {
      if (managedBackupSourceBuilder_ == null) {
        if (importSourcesCase_ == 24
            && importSources_
                != com.google.cloud.memorystore.v1.Instance.ManagedBackupSource
                    .getDefaultInstance()) {
          importSources_ =
              com.google.cloud.memorystore.v1.Instance.ManagedBackupSource.newBuilder(
                      (com.google.cloud.memorystore.v1.Instance.ManagedBackupSource) importSources_)
                  .mergeFrom(value)
                  .buildPartial();
        } else {
          importSources_ = value;
        }
        onChanged();
      } else {
        if (importSourcesCase_ == 24) {
          managedBackupSourceBuilder_.mergeFrom(value);
        } else {
          managedBackupSourceBuilder_.setMessage(value);
        }
      }
      importSourcesCase_ = 24;
      return this;
    }
<pre>
Optional. Immutable. Backups that generated and managed by memorystore
service.
</pre>

<code>
.google.cloud.memorystore.v1.Instance.ManagedBackupSource managed_backup_source = 24 [(.google.api.field_behavior) = OPTIONAL, (.google.api.field_behavior) = IMMUTABLE];
</code>
java-valkey/proto-google-cloud-valkey-v1/src/main/java/com/google/cloud/memorystore/v1/Instance.java