code: public Map<String, String> getHeaders() throws ApiException {
          ApiResponse<Map<String, String>> resp = getHeadersWithHttpInfo();
          return resp.getData();
      }
docs: Debug request headers Echo the request headers for debugging purposes.
  Note that the &#39;Connection&#39; header and any &#39;X-&#39; headers
  are not included
  
  @return Map&lt;String, String&gt;
  @throws ApiException
  If fail to call the API, e.g. server error or cannot
  deserialize the response body