$this->drupalGet('node/add/article');
$this->assertText($label, 'Block was displayed on the node/add/article page.');
$this->assertCacheContexts(['languages:language_content', 'languages:language_interface', 'session', 'theme', 'url.path', 'url.query_args', 'user', 'route']);
$this->drupalGet('node/add/article');
$this->assertText($label, 'Block was displayed on the node/add/article page.');
$this->assertCacheContexts(['languages:language_content', 'languages:language_interface', 'session', 'theme', 'url.path', 'url.query_args', 'user', 'route']);