@Test
void shouldHandleDuplicateHeaders() {

    final HttpRequest delegate = post("/");
    delegate.addHeader("Content-Type", "text/plain;");
    delegate.addHeader("Content-Type", "text/plain;");
    final LocalRequest unit = unit(delegate);
    assertThat(unit.getHeaders(), aMapWithSize(1));
    assertThat(unit.getHeaders().get("Content-Type"), hasSize(2));
}