public function testEscapeMarkdown()
 {
     // Username.
     $user = new User(['id' => 1, 'first_name' => 'John', 'last_name' => 'Taylor', 'username' => 'j_taylor']);
     self::assertEquals('@j_taylor', $user->tryMention());
     self::assertEquals('@j\\_taylor', $user->tryMention(true));
     // First name.
     $user = new User(['id' => 1, 'first_name' => 'John[']);
     self::assertEquals('John[', $user->tryMention());
     self::assertEquals('John\\[', $user->tryMention(true));
     // First and Last name.
     $user = new User(['id' => 1, 'first_name' => 'John', 'last_name' => '`Taylor`']);
     self::assertEquals('John `Taylor`', $user->tryMention());
     self::assertEquals('John \\`Taylor\\`', $user->tryMention(true));
     // Plain escapeMarkdown functionality.
     self::assertEquals('a\\`b\\[c\\*d\\_e', $user->escapeMarkdown('a`b[c*d_e'));
 }