public static com.google.cloud.vertexai.api.RagRetrievalConfig.Filter parseDelimitedFrom(
        java.io.InputStream input, com.google.protobuf.ExtensionRegistryLite extensionRegistry)
        throws java.io.IOException {
      return com.google.protobuf.GeneratedMessageV3.parseDelimitedWithIOException(
          PARSER, input, extensionRegistry);
    }
<pre>
Optional. String for metadata filtering.
</pre>

<code>string metadata_filter = 2 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The bytes for metadataFilter.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/RagRetrievalConfig.java