ConstReturns the module defined with key.
Returns every defined module.
Loads modules ahead of use, one at a time while the host is idle.
Loads nothing while offline or when the connection asks to save data, and no rare modules on
a slow connection. Stops as soon as that changes, so call it again when the connection
recovers; modules that already loaded are skipped. Modules defined with prefetch: false are
never loaded ahead of use. A module that fails to load is left for its first use to retry.
The modules defined with defineLazyModule.