I don't know much about access-modifier. Is it right to understand like this?:
* `NoExternalUse` stands for "do not use from packages other than `core`"
* That is put to prevent access to `AsynchPeople#getModified` from plugins.
* Though `test` package accesses to `AsynchPeople#getModified`, that doesn't matter for `access-modifier-checker ` is not configured for `test` package.