   }
 }
 
+extension SequenceType {
+  final public func _customContainsEquatableElement(
+    element: Generator.Element
+  ) -> Bool? {
+    return nil
+  }
+}
+
 public struct _CopyToNativeArrayBuffer {}
 public func _copyToNativeArrayBuffer<Args>(args: Args)
   -> (_CopyToNativeArrayBuffer, Args)


  /// Copy a Sequence into an array.
  func ~> (source:Self, ptr:(_InitializeTo, UnsafeMutablePointer<Generator.Element>))
}

extension SequenceType {

  func generate() -> Generator
}

/// This protocol is an implementation detail of `SequenceType`; do
/// not use it directly.
///
