@brief Test (with asserts) what Ryan thinks are the invariants. Will inline right out of existence in non-debug builds.

@brief Helper to create the default return value, in possible anticipation of a non-void and policy-based default return value.

@brief Helper to actually update the last input and perform invocation

@brief Takes in an array of objects, and passes them each, in order, to m_processObject()

@brief Process a name:value entry in an alias description object, with the given priority. Calls m_processSingleEntry() to actually complete its work.

@brief Takes in an object, retrieves the priority specified by the PRIORITY_KEY, if any, then passes all other entries in the object to m_processEntry

@brief Called for each individual alias path to be processed for (and potentially added to/updated in) the path tree.

@brief Given a path, remove any existing handler for that path from both the handler container and the interface tree.