@macro action
Converts this object to a string (calling to_s), converts it to a JSON string, and returns the result. This is a fallback, if no special method to_json was defined for some object.
Returns a JSON string containing a JSON object, that is generated from this Hash instance. state is a JSON::State object, that can also be used to configure the produced JSON string output further.
Returns a JSON string containing a JSON array, that is generated from this Array instance. state is a JSON::State object, that can also be used to configure the produced JSON string output further.