public static com.google.cloud.translate.v3.ListAdaptiveMtDatasetsRequest parseFrom(
      com.google.protobuf.ByteString data,
      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
      throws com.google.protobuf.InvalidProtocolBufferException {
    return PARSER.parseFrom(data, extensionRegistry);
  }
<pre>
Optional. An expression for filtering the results of the request.
Filter is not supported yet.
</pre>

<code>string filter = 4 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The bytes for filter.
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/ListAdaptiveMtDatasetsRequest.java