boundary = "simple boundary",
        source = Buffer().writeUtf8(multipart),
      )

    assertThat(parts.nextPart()).isNotNull()
    assertThat(parts.nextPart()).isNull()
    assertThat(parts.nextPart()).isNull()
  }

  @Test fun `empty source`() {
    val parts =
      MultipartReader(
        boundary = "simple boundary",
        source = Buffer(),
      )

// Validates the preconditions for CopyObjectPart, returns true if CopyObjectPart
// operation should not proceed. Preconditions supported are:
//
//	x-amz-copy-source-if-modified-since
//	x-amz-copy-source-if-unmodified-since
//	x-amz-copy-source-if-match
//	x-amz-copy-source-if-none-match
func checkCopyObjectPartPreconditions(ctx context.Context, w http.ResponseWriter, r *http.Request, objInfo ObjectInfo) bool {

        try {
            final RESULT result = entityType.newInstance();
            result.setCreatedTime(DfTypeUtil.toLong(source.get("createdTime")));
            result.setExpiredTime(DfTypeUtil.toLong(source.get("expiredTime")));
            result.setName(DfTypeUtil.toString(source.get("name")));

    while (true) {
      when (source.select(options)) {
        in 0..2 -> {
          completeEvent(id, type, data)
          return true
        }

        in 3..4 -> {
          source.readData(data)
        }

        in 5..7 -> {
          data.writeByte('\n'.code) // 'data' on a line of its own.
        }

        in 8..9 -> {
          id = source.readUtf8LineStrict().takeIf { it.isNotEmpty() }

  override fun write(
    source: Buffer,
    byteCount: Long,
  ) {
    if (byteCount == 0L) return // Avoid double-triggering.

    if (bytesWritten == triggerByteCount) {
      source.skip(byteCount)
      return
    }

    val toWrite = minOf(byteCount, triggerByteCount - bytesWritten)
    bytesWritten += toWrite

    delegate.write(source, toWrite)

    if (bytesWritten == triggerByteCount) {

      if (!endpointPair.isOrdered()) {
        return false;
      }

      Object source = endpointPair.source();
      Object target = endpointPair.target();
      return (node.equals(source) && graph.successors(node).contains(target))
          || (node.equals(target) && graph.predecessors(node).contains(source));
    } else {
      if (endpointPair.isOrdered()) {
        return false;
      }

      object : RequestBody() {
        override fun contentType() = contentType

        override fun contentLength() = length()

        override fun writeTo(sink: BufferedSink) {
          source().use { source -> sink.writeAll(source) }
        }
      }

    /** Returns a new request body that transmits the content of this. */
    @JvmStatic
    @JvmName("create")
    fun Path.asRequestBody(

        return invalidIndexDateFields(source).isEmpty();
    }

    default List<String> invalidIndexDateFields(final Map<String, Object> source) {
        return split(getIndexAdminDateFields(), ",").get(
                stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).filter(s -> isNonEmptyValue(source.get(s))).filter(s -> {

            result.setTargetRole(DfTypeUtil.toString(source.get("targetRole")));
            result.setUpdatedBy(DfTypeUtil.toString(source.get("updatedBy")));
            result.setUpdatedTime(DfTypeUtil.toLong(source.get("updatedTime")));
            return updateEntity(source, result);
        } catch (InstantiationException | IllegalAccessException e) {

            result.setUpdatedBy(DfTypeUtil.toString(source.get("updatedBy")));
            result.setUpdatedTime(DfTypeUtil.toLong(source.get("updatedTime")));
            result.setUrlExpr(DfTypeUtil.toString(source.get("urlExpr")));
            return updateEntity(source, result);
        } catch (InstantiationException | IllegalAccessException e) {