5. Search for our widget using a Finder

With a widget in the test environment, search
through the widget tree for the title and message
Text widgets using a Finder. This allows verification that
the widgets are being displayed correctly.

For this purpose, use the top-level find()
method provided by the flutter_test package to create the Finders.
Since you know you’re looking for Text widgets, use the
find.text() method.

For more information about Finder classes, see the
Finding widgets in a widget test recipe.

6. Verify the widget using a Matcher

Finally, verify the title and message Text widgets appear on screen
using the Matcher constants provided by flutter_test.
Matcher classes are a core part of the test package,
and provide a common way to verify a given
value meets expectations.

Ensure that the widgets appear on screen exactly one time.
For this purpose, use the findsOneWidget Matcher.