package—a package designator.
symbols—a list of symbols.
Returns a list of symbols that have been declared
as shadowing symbols in package by
shadowing-import (or the equivalent
All symbols on this list are present in package.
(package-shadowing-symbols (make-package 'temp)) → () (shadow 'cdr 'temp) → T (package-shadowing-symbols 'temp) → (TEMP::CDR) (intern "PILL" 'temp) → TEMP::PILL, NIL (shadowing-import 'pill 'temp) → T (package-shadowing-symbols 'temp) → (PILL TEMP::CDR)
Should signal an error of type
type-error if package is not a package designator.
Whether the list of symbols is fresh is implementation-dependent.