Package-level declarations

The identifier of the MQTT client whose connection is being addressed. AWS caps it at 128 characters and reserves the $ prefix.

The name of a named shadow. Absence of a name addresses the unnamed ("classic") shadow. Constrained to the charset and length AWS documents for a shadow name.

AWS does not allow slashes in a thing name, which is what lets it be dropped straight into the /things/{thingName}/shadow path.

Only checked for being non-blank. MQTT topics are slash-separated and can contain $ (reserved topics) and spaces, so the stricter pattern used for thing and shadow names would reject valid topics.