anchor.diff:    /// Eagerly selects a trailing sequence of characters.
     ///
     /// Checks each character, from first to last, against [test],
  -  /// until one is found whwere [test] returns `false`.
  +  /// until one is found where [test] returns `false`.
     /// The characters starting with the first one
     /// where [test] returns `false`, are included in the result.
     ///
  
positive.code:   /// Eagerly selects a leading sequence of characters.
    ///
    /// Checks each character, from last to first, against [test],
    /// until one is found whwere [test] returns `false`.
    /// The characters up to and including the one with the latest index
    /// where [test] returns `false` are included in the result.
    ///
  
negative.code:   /// Eagerly selects a leading sequence of characters.
    ///
    /// Checks each character, from first to last, against [test],
    /// until one is found where [test] returns `false`.
    /// The characters up to, but not including, the first one
    /// where [test] returns `false` are included in the result.
    ///
  