src/Concerns/MakesHttpRequests.php
public function withHeader(string $name, string $value)
    {
        $this->defaultHeaders[$name] = $value;

        return $this;
    }
public function withHeader(string $name, string $value)
    {
        $this->defaultHeaders[$name] = $value;

        return $this;
    }
public function withHeader ( string $ name , string $ value ) { $ this -> defaultHeaders [ $ name ] = $ value ; return $ this ; }
Add a header to be sent with the request.

@param  string $name
@param  string $value
@return $this
Add a header to be sent with the request .