anchor.diff:  import 'icon.dart';
   import 'icon_theme.dart';
   import 'icon_theme_data.dart';
  -import 'material.dart';
   import 'text_selection.dart';
   import 'theme.dart';
   
   export 'package:flutter/services.dart' show TextInputType;
   
  +const Duration _kTransitionDuration = const Duration(milliseconds: 200);
  +const Curve _kTransitionCurve = Curves.fastOutSlowIn;
  +
  +/// A simple text input field.
  +///
  +/// This widget is comparable to [Text] in that it does not include a margin
  +/// or any decoration outside the text itself. It is useful for applications,
  +/// like a search box, that don't need any additional decoration. It should
  +/// also be useful in custom widgets that support text input.
  +///
  +/// The [value] field must be updated each time the [onChanged] callback is
  +/// invoked. Be sure to include the full [value] provided by the [onChanged]
  +/// callback, or information like the current selection will be lost.
  +///
  +/// Requires one of its ancestors to be a [Material] widget.
  +///
  +/// See also:
  +///
  +/// * [Input], which adds a label, a divider below the text field, and support for
  +///   an error message.
   class InputField extends StatefulWidget {
     InputField({
       Key key,
  
positive.code:   }
  }
  
  /// A material design text input field.
  ///
  /// Requires one of its ancestors to be a [Material] widget.
  ///
  /// The [value] field must be updated each time the [onChanged] callback is
  /// invoked. Be sure to include the full [value] provided by the [onChanged]
  /// callback, or information like the current selection will be lost.
  ///
  /// See also:
  ///
  ///  * <https://material.google.com/components/text-fields.html>
  
negative.code:   ///
    /// By default, the input uses a keyboard appropriate for text entry.
    //
    //  If you change this constructor signature, please also update
    // InputContainer, InputFormField, InputField.
    Input({
      Key key,
      this.value,
  