ExpressiveInstaller\OptionalPackages::removeDevDependencies PHP Method

    public static function removeDevDependencies()
    {
        foreach (self::$devDependencies as $devDependency) {
            unset(self::$stabilityFlags[$devDependency]);
            unset(self::$composerDevRequires[$devDependency]);
            unset(self::$composerDefinition['require-dev'][$devDependency]);
        }
    }

 public function testDevDependenciesAreRemoved()
 {
     // Prepare the installer
     OptionalPackages::removeDevDependencies();
     $this->assertComposerHasPackages($this->standardDependencies);
     $this->assertComposerNotHasPackages($this->devDependencies);
 }