@Test
  @EnabledIfSystemProperty(named = "sun.net.http.allowRestrictedHeaders", matches = "true")
  public void noRequestBodyForPostWithAllowRestrictedHeaders() throws Exception {
    super.noResponseBodyForPost();
    MockWebServerAssertions.assertThat(server.takeRequest())
        .hasMethod("POST")
        .hasNoHeaderNamed("Content-Type")
        .hasHeaders(entry("Content-Length", Collections.singletonList("0")));
  }
We currently don't include the <a href="http://java.net/jira/browse/JERSEY-639">60-line
workaround</a> jersey uses to overcome the lack of support for PATCH. For now, prefer okhttp.

@see java.net.HttpURLConnection#setRequestMethod
core/src/test/java/feign/client/DefaultClientTest.java