@java.lang.Override
    public final boolean isInitialized() {
      byte isInitialized = memoizedIsInitialized;
      if (isInitialized == 1) return true;
      if (isInitialized == 0) return false;

      memoizedIsInitialized = 1;
      return true;
    }
<pre>
Optional. rag_file_id. The files should be in the same rag_corpus set in
rag_corpus field.
</pre>

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

@param index The index of the value to return.
@return The bytes of the ragFileIds at the given index.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/VertexRagStore.java