Crashing on iOS 13.2

[Max Cobb]

Describe the bug
When using iOS 13.2 this class does not work when imported as a Swift Package.

To Reproduce
Steps to reproduce the behavior:

1. Add package to project
2. Run on iOS 13.2
3. See crash when even creating any of the given classes

Expected behavior
No crash, should work as in previous iOS versions.

Environment:

• iOS Version: 13.2
• Device Information: iPhone 11 Pro
• Xcode Version: 11.1

Additional context
Works fine when adding the swift files individually, as with the Example in this repo

[Max Cobb]

A fix for the bug has been added to the README.

Read more about it here:
https://bugs.swift.org/browse/SR-11564