docs: improved description

Co-authored-by: Lonnie Ezell <lonnieje@gmail.com>

Author: datamweb

docs/references/testing.md

@@ -36,7 +36,7 @@ class ActionsTest extends TestCase
 
 ## Improving the Speed of Running Tests
 
-By default, the Shield has set the `Config\Auth::$hashCost = 12` due to the greater security of passwords. However, to increase the test execution time, we have set the `$hashCost = 4` for the test environment.
+By default, Shield has set the `Config\Auth::$hashCost = 12` due to the greater security of passwords. However, to increase the test execution time, we have set the `$hashCost = 4` for the test environment.
 
 If you use Shield in your project and your tests execution time is high, just set the `$hashCost = 4` in file **phpunit.xml.dist** of your project as follows: