public Builder setFilter(com.google.cloud.vertexai.api.RagRetrievalConfig.Filter value) {
      if (filterBuilder_ == null) {
        if (value == null) {
          throw new NullPointerException();
        }
        filter_ = value;
      } else {
        filterBuilder_.setMessage(value);
      }
      bitField0_ |= 0x00000002;
      onChanged();
      return this;
    }
<pre>
Optional. Config for filters.
</pre>

<code>
.google.cloud.vertexai.v1.RagRetrievalConfig.Filter filter = 3 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/RagRetrievalConfig.java