code: public static Request create(String method,
                                 String url,
                                 Map<String, Collection<String>> headers,
                                 byte[] body,
                                 Charset charset) {
      checkNotNull(method, "httpMethod of %s", method);
      HttpMethod httpMethod = HttpMethod.valueOf(method.toUpperCase());
      return create(httpMethod, url, headers, body, charset);
    }
docs: No parameters can be null except {@code body} and {@code charset}. All parameters must be
  effectively immutable, via safe copies, not mutating or otherwise.
  
  @deprecated {@link #create(HttpMethod, String, Map, byte[], Charset)}