captureThat function Null safety

Null captureThat(
  1. Matcher matcher,
  2. {String? named}
)

An argument matcher that matches an argument that matches matcher, and captures the argument for later access with captured.

Implementation

Null captureThat(Matcher matcher, {String? named}) =>
    _registerMatcher(matcher, true,
        named: named, argumentMatcher: 'captureThat');