in Sources/_CollectionsTestSupport/MinimalTypes/_MinimalCollectionCore.swift [87:100]
func assertValidIndexBeforeEnd(
_ index: MinimalIndex,
_ message: @autoclosure () -> String = "Invalid index",
file: StaticString = #file,
line: UInt = #line
) {
expectTrue(isValidIndex(index),
message(), trapping: true,
file: file, line: line)
expectTrue(index._offset != elements.count,
message(), trapping: true,
file: file, line: line)
}