public HttpRequest headers(final Map<String, String> headers) {
    if (!headers.isEmpty())
      for (Entry<String, String> header : headers.entrySet())
        header(header);
    return this;
  }
Set all headers found in given map where the keys are the header names and
the values are the header values

@param headers
@return this request
lib/src/main/java/com/github/kevinsawicki/http/HttpRequest.java