lazyIncomplete

Answer the bundle trees that are waiting for a specific token to be parsed. These are organized as a two-layer map. The outer map is keyed by the A_String form of an expected token, and each corresponding inner map is from the keyword index to the successor A_BundleTree representing the situation where a token matching the key was consumed, and it had the keyword index that led to this new bundle tree.

The two layered map allows the correct keyword index to be captured with a consumed token during parsing.

This is only an authoritative map if an expand has been invoked since the last modification via methods like addPlanInProgress.