AssertNoDependency checks that the given import paths (the keys) do not depend (transitively) on certain banned imports (the values).

AssertOnlyDependencies checks that the given import paths (the keys) only depend (transitively) on certain allowed imports (the values).

CheckNoDependency checks that the given import paths (ip) does not depend (transitively) on certain banned imports.

CheckOnlyDependencies checks that the given import path only depends (transitively) on certain allowed imports.

StdlibPackages returns the list of all standard library packages, including some golang.org/x/ dependencies.