/**
  * @covers DmMailer\Form\MessageForm
  */
 public function testBuild()
 {
     $this->sut->build();
     $this->assertInstanceOf('Zend\\Form\\Element\\Hidden', $this->sut->get(Form::ENTITY_ID));
     $this->assertInstanceOf('Zend\\Form\\Element\\Hidden', $this->sut->get(Form::ON_HALT));
     $this->assertInstanceOf('Zend\\Form\\Element\\Text', $this->sut->get(Form::SUBJECT));
     $this->assertInstanceOf('Zend\\Form\\Element\\Textarea', $this->sut->get(Form::BODY));
     $this->assertInstanceOf('Zend\\Form\\Element\\Select', $this->sut->get(Form::CAMPAIGN));
     $this->assertInstanceOf('Zend\\Form\\Element\\Text', $this->sut->get(Form::SEND_AT));
     $this->assertInstanceOf('Zend\\Form\\Element\\Csrf', $this->sut->get(Form::SECURITY));
 }