code: public RequestBuilder handleHeaders(Map<String, Object> headers, RequestBuilder requestBuilder) {
          Map<String, Object> amendedHeaders = amendRequestHeaders(headers);
          processFrameworkDefault(amendedHeaders, requestBuilder);
          return requestBuilder;
      }
docs: The framework will fall back to this default implementation to handle the headers.
  If you want to override any headers, you can do that by overriding the
  amendRequestHeaders(headers) method.
  
  @param headers
  @param requestBuilder
  @return : An effective Apache http request builder object with processed headers.