The json string can contain one or more machine definitions.
The correct machine will be found from the json structure.
This class provides a way to load json from a file on your file system (fast access)
and is also used by the Redis adapter to load a json string from a redis server.
The format of the data to be loaded is specified via a json-schema.
The schema can be retrieved via JSON::getJSONSchema() and the schema itself and
a full example of the data can be found in 'assets/json'