/**
     * Gets the global Toolchains source.
     *
     * @return the global Toolchains source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getGlobalToolchainsSource();

    /**
     * Gets the user Toolchains source.
     *
     * @return the user Toolchains source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getUserToolchainsSource();

    @Nonnull

            Severity severity,
            Version version,
            String source,
            int lineNumber,
            int columnNumber,
            String modelId,
            Exception exception) {
        this.message = message;
        this.severity = (severity != null) ? severity : Severity.ERROR;
        this.source = (source != null) ? source : "";
        this.lineNumber = lineNumber;

    assertEquals(STRING.length(), source.copyTo(sink));
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());
    assertTrue(sink.wasStreamOpened() && sink.wasStreamClosed());

    assertEquals(STRING, sink.getString());
  }

  public void testRead_toString() throws IOException {
    assertEquals(STRING, source.read());
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());
  }

	if sourceEndpoint == "" {
		log.Fatalln("source Endpoint is not provided")
	}

	if sourceAccessKey == "" {
		log.Fatalln("source Access key is not provided")
	}

	if sourceSecretKey == "" {
		log.Fatalln("source Secret key is not provided")
	}

	if sourceBucket == "" && sourcePrefix != "" {
		log.Fatalln("--source-prefix is specified without --source-bucket.")
	}

	if targetEndpoint == "" {

            result.setCreatedTime(DfTypeUtil.toLong(source.get("createdTime")));
            result.setDepth(DfTypeUtil.toInteger(source.get("depth")));
            result.setDescription(DfTypeUtil.toString(source.get("description")));
            result.setExcludedDocPaths(DfTypeUtil.toString(source.get("excludedDocPaths")));
            result.setExcludedPaths(DfTypeUtil.toString(source.get("excludedPaths")));

        this.configuration = null;
    }

    public MojoExecution(MojoDescriptor mojoDescriptor, String executionId, Source source) {
        this.mojoDescriptor = mojoDescriptor;
        this.executionId = executionId;
        this.configuration = null;
        this.source = source;
    }

    public MojoExecution(MojoDescriptor mojoDescriptor, String executionId) {
        this.mojoDescriptor = mojoDescriptor;

            result.setLanguages(DfTypeUtil.toString(source.get("languages")));
            result.setQueryId(DfTypeUtil.toString(source.get("queryId")));
            result.setQueryOffset(DfTypeUtil.toInteger(source.get("queryOffset")));
            result.setQueryPageSize(DfTypeUtil.toInteger(source.get("queryPageSize")));
            result.setQueryTime(DfTypeUtil.toLong(source.get("queryTime")));

    }

    public void setSource(String source) {
        this.source = source;
        this.sourceModel = null;
    }

    public void setSource(Model source) {
        this.sourceModel = source;
        this.source = null;

        if (rootModel == null) {
            rootModel = source;
        }
    }

    private String getSource() {
        if (source == null && sourceModel != null) {

    String string = source.read();
    assertExpectedString(string);
  }

  public void testReadFirstLine() throws IOException {
    if (expectedLines.isEmpty()) {
      assertNull(source.readFirstLine());
    } else {
      assertEquals(expectedLines.get(0), source.readFirstLine());
    }
  }

  public void testReadLines_toList() throws IOException {
    assertExpectedLines(source.readLines());
  }

 */
internal class DerReader(source: Source) {
  private val countingSource: CountingSource = CountingSource(source)
  private val source: BufferedSource = countingSource.buffer()

  /** Total bytes read thus far. */
  private val byteCount: Long
    get() = countingSource.bytesRead - source.buffer.size