public Builder addRagFileIdsBytes(com.google.protobuf.ByteString value) {
        if (value == null) {
          throw new NullPointerException();
        }
        checkByteStringIsUtf8(value);
        ensureRagFileIdsIsMutable();
        ragFileIds_.add(value);
        bitField0_ |= 0x00000002;
        onChanged();
        return this;
      }
<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 value The bytes of the ragFileIds to add.
@return This builder for chaining.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/VertexRagStore.java