@java.lang.Override
  public com.google.protobuf.ByteString getCacheControlBytes() {
    java.lang.Object ref = cacheControl_;
    if (ref instanceof java.lang.String) {
      com.google.protobuf.ByteString b =
          com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
      cacheControl_ = b;
      return b;
    } else {
      return (com.google.protobuf.ByteString) ref;
    }
  }
<pre>
Optional. Updates objects Cache-Control fixed metadata. Unset values will
be
 ignored. Set empty values to clear the metadata.
 Additionally, the value for Custom-Time cannot decrease. Refer to
 documentation in
https://cloud.google.com/storage/docs/metadata#caching_data.
</pre>

<code>optional string cache_control = 5 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The bytes for cacheControl.
java-storagebatchoperations/proto-google-cloud-storagebatchoperations-v1/src/main/java/com/google/cloud/storagebatchoperations/v1/PutMetadata.java