public static Builder newBuilder(
      com.google.cloud.vision.v1p3beta1.ProductSearchParams prototype) {
    return DEFAULT_INSTANCE.toBuilder().mergeFrom(prototype);
  }
<pre>
The filtering expression. This can be used to restrict search results based
on Product labels. We currently support an AND of OR of key-value
expressions, where each expression within an OR must have the same key. An
'=' should be used to connect the key and value.

For example, "(color = red OR color = blue) AND brand = Google" is
acceptable, but "(color = red OR brand = Google)" is not acceptable.
"color: red" is not acceptable because it uses a ':' instead of an '='.
</pre>

<code>string filter = 8;</code>

@return The bytes for filter.
java-vision/proto-google-cloud-vision-v1p3beta1/src/main/java/com/google/cloud/vision/v1p3beta1/ProductSearchParams.java