public function testReplaceHeaders()
{
$options = (new HttpOptions())->addHeader('Foo: bar')->addHeader('Foo: baz')->addHeader($qux = 'Qux: Quux');
$options->replaceHeaders('Foo', $foo = 'Foo: corge');
self::assertContains($qux, $options->getHeaders());
self::assertContains($foo, $options->getHeaders());
self::assertCount(2, $options->getHeaders());
}