} catch (_: NumberFormatException) {
        invalidLengths(strings)
      }
    }

    /** Append space-prefixed lengths to [writer]. */
    @Throws(IOException::class)
    internal fun writeLengths(writer: BufferedSink) {
      for (length in lengths) {
        writer.writeByte(' '.code).writeDecimalLong(length)
      }
    }

    @Throws(IOException::class)