Google\Spreadsheet\DefaultServiceRequest::removeHeader PHP Method

    public function removeHeader($name)
    {
        if (array_key_exists($name, $this->headers)) {
            unset($this->headers[$name]);
        }
        return $this;
    }

 public function testRemoveHeader()
 {
     $request = new DefaultServiceRequest("token");
     $headers = ["k" => "v"];
     $request->addHeader("k", "v");
     $this->assertEquals($headers, $request->getHeaders());
     $this->assertTrue($request->removeHeader("k") instanceof DefaultServiceRequest);
     $this->assertEquals([], $request->getHeaders());
 }