   //     commonPrefixWithString:(NSString *)aString
   //     options:(StringCompareOptions)mask
 
-  /// Returns a string containing characters the `String` and a
+  /// Returns a string containing characters this string and the
   /// given string have in common, starting from the beginning of each
   /// up to the first characters that aren't equivalent.
   public func commonPrefix(

  //         BOOL *stop)
  //       )block

  /// Enumerates the substrings of the specified type in the
  /// specified range of the string.
  public func enumerateSubstrings(
    in range: Range<Index>,
    options opts: EnumerationOptions = [],

  //     length:(NSUInteger)length
  //     freeWhenDone:(BOOL)flag

  /// Creates a new string that contains the specified
  /// number of characters from a given array of UTF-16 Code Units
  public init(
    utf16CodeUnitsNoCopy: UnsafePointer<unichar>,
