if (!"Vary".equals(name(i), ignoreCase = true)) {
          continue
        }

        val value = value(i)
        if (result == null) {
          result = TreeSet(String.CASE_INSENSITIVE_ORDER)
        }
        for (varyField in value.split(',')) {
          result.add(varyField.trim())
        }
      }
      return result ?: emptySet()
    }

    /**