public static Request create(
      HttpMethod httpMethod,
      String url,
      Map<String, Collection<String>> headers,
      Body body,
      RequestTemplate requestTemplate) {
    return new Request(httpMethod, url, headers, body, requestTemplate);
  }
Builds a Request. All parameters must be effectively immutable, via safe copies.

@param httpMethod for the request.
@param url for the request.
@param headers to include.
@param body of the request, can be {@literal null}
@return a Request
core/src/main/java/feign/Request.java