/**
     * @test
     */
    public function itShouldWriteUnionAllFromGenericBuilder()
    {
        $minus = $this->writer->minus(new Select('user'), new Select('user_email'));
        $expected = <<<SQL
SELECT user.* FROM user
MINUS
SELECT user_email.* FROM user_email
SQL;
        $this->assertEquals($expected, $this->writer->write($minus));
    }
 /**
  * @test
  */
 public function itShouldCreateMinusObject()
 {
     $className = '\\NilPortugues\\Sql\\QueryBuilder\\Manipulation\\Minus';
     $this->assertInstanceOf($className, $this->writer->minus(new Select('table1'), new Select('table2')));
 }