public com.google.protobuf.ByteString getFilterBytes() {
      java.lang.Object ref = filter_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        filter_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Filtering results.
</pre>

<code>string filter = 4;</code>

@return The bytes for filter.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/ListEventsRequest.java