public function testWithHeaderReplacesDifferentCase() { $response = new Response(200, ['Foo' => 'Bar']); $response2 = $response->withHeader('foO', 'Bam'); $this->assertSame(['Foo' => ['Bar']], $response->getHeaders()); $this->assertSame(['foO' => ['Bam']], $response2->getHeaders()); $this->assertSame('Bam', $response2->getHeaderLine('foo')); $this->assertSame(['Bam'], $response2->getHeader('foo')); }