code: private static Map<String, Object> getExtraHeaders(String clazz, ITestContext context) {
          return (Map<String, Object>) context.getAttribute(clazz + "Headers");
      }
docs: Obtains the additional headers of the current test suite being executed. If no additional headers
  were set, null will be returned
  
  @param clazz   - the test suite class, used for making threadsafe storage of
  application, allowing suites to have independent applications
  under test, run at the same time
  @param context - the TestNG context associated with the test suite, used for
  storing app url information
  @return Map<String, String>: the key-pair values of the headers of the current test being executed