src/Message.php
public function getHeaderLine($name)
	{
		if (!$this->hasHeader($name)) {
			return null;
		}

		return implode(',', $this->getHeader($name));
	}
public function getHeaderLine($name)
	{
		if (!$this->hasHeader($name)) {
			return null;
		}

		return implode(',', $this->getHeader($name));
	}
{@inheritdoc}