public com.google.protobuf.ByteString getBackupIdBytes() {
      java.lang.Object ref = backupId_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        backupId_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Optional. The id of the backup to be created. If not specified, the
default value ([YYYYMMDDHHMMSS]_[Shortened Instance UID] is used.
</pre>

<code>optional string backup_id = 3 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The bytes for backupId.
java-valkey/proto-google-cloud-valkey-v1/src/main/java/com/google/cloud/memorystore/v1/BackupInstanceRequest.java