private void ensureFacetResultsIsMutable() {
      if (!((bitField0_ & 0x00000004) != 0)) {
        facetResults_ =
            new java.util.ArrayList<com.google.cloud.visionai.v1.FacetGroup>(facetResults_);
        bitField0_ |= 0x00000004;
      }
    }
<pre>
The next-page continuation token.
</pre>

<code>string next_page_token = 2;</code>

@param value The bytes for nextPageToken to set.
@return This builder for chaining.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/SearchAssetsResponse.java