private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.video.livestream.v1.Encryption.DrmSystems,
            com.google.cloud.video.livestream.v1.Encryption.DrmSystems.Builder,
            com.google.cloud.video.livestream.v1.Encryption.DrmSystemsOrBuilder>
        getDrmSystemsFieldBuilder() {
      if (drmSystemsBuilder_ == null) {
        drmSystemsBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.video.livestream.v1.Encryption.DrmSystems,
                com.google.cloud.video.livestream.v1.Encryption.DrmSystems.Builder,
                com.google.cloud.video.livestream.v1.Encryption.DrmSystemsOrBuilder>(
                getDrmSystems(), getParentForChildren(), isClean());
        drmSystems_ = null;
      }
      return drmSystemsBuilder_;
    }
<pre>
Required. Configuration for DRM systems.
</pre>

<code>
.google.cloud.video.livestream.v1.Encryption.DrmSystems drm_systems = 3 [(.google.api.field_behavior) = REQUIRED];
</code>
java-video-live-stream/proto-google-cloud-live-stream-v1/src/main/java/com/google/cloud/video/livestream/v1/Encryption.java