GFunc wraps a function to make it lazy.

SyncFuncErr wraps a function to make it lazy.

SyncFunc wraps a function to make it lazy.

SyncFuncErr wraps a function to make it lazy.

DeferredFuncs allows one or more funcs to be deferred until the owner's [DeferredInit.Do] method is called for the first time.

DeferredInit allows one or more funcs to be deferred until [DeferredInit.Do] is called for the first time.

GValue is a lazily computed value.

SyncValue is a lazily computed value.

TB is a subset of testing.TB that we use to set up test helpers.