     }
   }
   
-  /// Evaluates the given transform closure when this `Result` instance is
-  /// `.failure`, passing the error as a parameter.
+  /// Evaluates the given closure when this `Result` instance is `.failure`,
+  /// passing the failure value as a parameter.
   ///
   /// Use the `mapError` method with a closure that returns a non-`Result`
   /// value.
   ///
   /// - Parameter transform: A closure that takes the failure value of the
   ///   instance.
-  /// - Returns: A new `Result` instance with the result of the transform, if
-  ///   it was applied.
+  /// - Returns: A `Result` instance with the result of evaluating the given
+  ///   closure as the new failure value if this instance is `.failure`.
   public func mapError<NewFailure>(
     _ transform: (Failure) -> NewFailure
   ) -> Result<Success, NewFailure> {

    }
  }
  
  /// Attempts to get the `success` value as a throwing expression.
  ///
  /// - Returns: The success value, if the instance is a success.
  /// - Throws:  The failure value, if the instance is a failure.
  public func get() throws -> Success {
    switch self {
    case let .success(success):

  /// A failure, storing a `Failure` value.
  case failure(Failure)
  
  /// Evaluates the given closure when this `Result` instance is `.success`,
  /// passing the success value as a parameter.
  ///
  /// Use the `map` method with a closure that returns a non-`Result` value.
  ///
  /// - Parameter transform: A closure that takes the success value of the
  ///   instance.
  /// - Returns: A `Result` instance with the result of evaluating the given 
  ///   closure as the new success value if this instance is `.success`.
  public func map<NewSuccess>(
    _ transform: (Success) -> NewSuccess
  ) -> Result<NewSuccess, Failure> {
