public Builder mergeProduct(com.google.cloud.vision.v1.Product value) {
      if (productBuilder_ == null) {
        if (((bitField0_ & 0x00000001) != 0)
            && product_ != null
            && product_ != com.google.cloud.vision.v1.Product.getDefaultInstance()) {
          getProductBuilder().mergeFrom(value);
        } else {
          product_ = value;
        }
      } else {
        productBuilder_.mergeFrom(value);
      }
      if (product_ != null) {
        bitField0_ |= 0x00000001;
        onChanged();
      }
      return this;
    }
<pre>
Required. The Product resource which replaces the one on the server.
product.name is immutable.
</pre>

<code>.google.cloud.vision.v1.Product product = 1 [(.google.api.field_behavior) = REQUIRED];
</code>
java-vision/proto-google-cloud-vision-v1/src/main/java/com/google/cloud/vision/v1/UpdateProductRequest.java