private void ensureUrisIsMutable() {
      if (!uris_.isModifiable()) {
        uris_ = new com.google.protobuf.LazyStringArrayList(uris_);
      }
      bitField0_ |= 0x00000001;
    }
<pre>
The Google Cloud Storage location for the input content.
</pre>

Protobuf type {@code google.cloud.vertexai.v1.GcsSource}
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/GcsSource.java