public function testAddingGeneratedUniqueKeyWithPrefix()
 {
     $blueprint = new Blueprint('users');
     $blueprint->setTablePrefix('prefix_');
     $blueprint->unique('foo');
     $grammar = $this->getGrammar();
     $grammar->setTablePrefix('prefix_');
     $statements = $blueprint->toSql($this->getConnection(), $grammar);
     $this->assertEquals(1, count($statements));
     $this->assertEquals('alter table prefix_users add constraint prefix_users_foo_unique unique ( foo )', $statements[0]);
 }