public function getValue(string $name): ?string
    {
        if (isset($this->data[$name])) {
            return $this->data[$name]->value;
        }
        return null;
    }
public function getValue(string $name): ?string
    {
        if (isset($this->data[$name])) {
            return $this->data[$name]->value;
        }
        return null;
    }
public function getValue ( string $ name ) : ? string { if ( isset ( $ this -> data [ $ name ] ) ) { return $ this -> data [ $ name ] -> value ; } return null ; }
Returns the value of the header or null if not found.

@param string $name The name of the header.
@return string|null The value of the header requested of null if not found.
Returns the value of the header or null if not found .