responseHeaders: Headers,
    ): Headers {
      val varyFields = responseHeaders.varyFields()
      if (varyFields.isEmpty()) return Headers.EMPTY

      val result = Headers.Builder()
      for (i in 0 until requestHeaders.size) {
        val fieldName = requestHeaders.name(i)
        if (fieldName in varyFields) {
          result.add(fieldName, requestHeaders.value(i))
        }
      }