@java.lang.Override
    public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
      if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(scheme_)) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 1, scheme_);
      }
      getUnknownFields().writeTo(output);
    }
<pre>
Required. Specify the encryption scheme, supported schemes:
- `cenc` - AES-CTR subsample
- `cbcs`- AES-CBC subsample pattern
</pre>

<code>string scheme = 1 [(.google.api.field_behavior) = REQUIRED];</code>

@return The bytes for scheme.
java-video-live-stream/proto-google-cloud-live-stream-v1/src/main/java/com/google/cloud/video/livestream/v1/Encryption.java