@java.lang.Override
    public java.lang.String getRetailProductRecognitionIndex() {
      java.lang.Object ref = retailProductRecognitionIndex_;
      if (ref instanceof java.lang.String) {
        return (java.lang.String) ref;
      } else {
        com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
        java.lang.String s = bs.toStringUtf8();
        retailProductRecognitionIndex_ = s;
        return s;
      }
    }
<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 retailProductRecognitionIndex.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/CustomProcessorSourceInfo.java