public void serialize(DataOutputStream stream) throws IOException {
    ReadWriteIOUtils.write(functionName, stream);
    TypeUtil.serialize(returnType, stream);
    ReadWriteIOUtils.write(argumentTypes.size(), stream);
    for (Type type : argumentTypes) {
      TypeUtil.serialize(type, stream);
    }
  }
The absolute canonical name of the function.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/function/BoundSignature.java