     wrapValue: (OpaqueValue<Int>) -> C.Iterator.Element,
     extractValue: (C.Iterator.Element) -> OpaqueValue<Int>,
 
-    makeCollectionOfEquatable: ([CollectionWithEquatableElement.Iterator.Element]) -> CollectionWithEquatableElement,
-    wrapValueIntoEquatable: (MinimalEquatableValue) -> CollectionWithEquatableElement.Iterator.Element,
-    extractValueFromEquatable: ((CollectionWithEquatableElement.Iterator.Element) -> MinimalEquatableValue),
+    makeCollectionOfEquatable: (
+      [CollectionWithEquatableElement.Iterator.Element]
+    ) -> CollectionWithEquatableElement,
+
+    wrapValueIntoEquatable: (
+      MinimalEquatableValue) -> CollectionWithEquatableElement.Iterator.Element,
+
+    extractValueFromEquatable: (
+      CollectionWithEquatableElement.Iterator.Element) -> MinimalEquatableValue,
 
     checksAdded: Box<Set<String>> = Box([]),
     resiliencyChecks: CollectionMisuseResiliencyChecks = .all,

  public let position: Int
  public let expected: [Int]
  public let loc: SourceLoc

  init(
    collection: [Int], position: Int, expected: [Int],
    file: String = #file, line: UInt = #line

    collection: [ 1010, 2020, 3030, 4040, 5050 ],
    bounds: 0..<2,
    count: 5),
  
  // Slice an empty suffix.
  SubscriptRangeTest(
    expected: [],
