public function testUseHeaders() { $mail = new SendGrid\Mail(); $mail->addTo('*****@*****.**')->addBcc('*****@*****.**')->setFrom('*****@*****.**')->setSubject('Subject')->setHtml('Hello You'); $this->assertFalse($mail->useHeaders()); $mail->removeBcc('*****@*****.**'); $this->assertTrue($mail->useHeaders()); $mail->addCc('*****@*****.**'); $this->assertFalse($mail->useHeaders()); $mail->removeCc('*****@*****.**')->setRecipientsinHeader(true); $this->assertTrue($mail->useHeaders()); $mail->setRecipientsinHeader(false); $this->assertFalse($mail->useHeaders()); $mail->addBcc('*****@*****.**')->addAttachment('attachment.ext'); $this->assertTrue($mail->useHeaders()); }