public com.google.protobuf.ByteString getRetailProductRecognitionIndexBytes() {
        java.lang.Object ref = retailProductRecognitionIndex_;
        if (ref instanceof String) {
          com.google.protobuf.ByteString b =
              com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
          retailProductRecognitionIndex_ = b;
          return b;
        } else {
          return (com.google.protobuf.ByteString) ref;
        }
      }
<pre>
Required. Resource name of RetailProductRecognitionIndex.
Format is
'projects/&#42;&#47;locations/&#42;&#47;retailCatalogs/&#42;&#47;retailProductRecognitionIndexes/&#42;'
</pre>

<code>
string retail_product_recognition_index = 1 [(.google.api.field_behavior) = REQUIRED];
</code>

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