This value may be null.

If you want to migrate before this change lands,
you can add a class to your class
similar to the following:

abstract

class

_TemporaryTextEditingClient

TextEditingValue

get

currentTextEditingValue

This allows you to add the new member with an
@override annotation before the change lands
in the framework. Later, you can remove the
temporary interface definition.

Code before migration:

class

_MyCustomTextWidgetState

extends

State

MyCustomWidget

implements

TextEditingClient

...

@override

void

updateEditingValue

TextEditingValue

value

...

@override