public com.google.protobuf.ByteString getModalityBytes() {
        java.lang.Object ref = modality_;
        if (ref instanceof String) {
          com.google.protobuf.ByteString b =
              com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
          modality_ = b;
          return b;
        } else {
          return (com.google.protobuf.ByteString) ref;
        }
      }
<pre>
Modality of the feature. Valid values are: numeric, image. Defaults to
numeric.
</pre>

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

@return The bytes for modality.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/ExplanationMetadata.java