src/Neutrino/HttpClient/Header.php
public function has($name)
    {
        return isset($this->headers[$name]) || array_key_exists($name, $this->headers);
    }
public function has($name)
    {
        return isset($this->headers[$name]) || array_key_exists($name, $this->headers);
    }
Determine if a header exists with a specific key.

@param string $name

@return boolean