* atomic: a read observes the full set of values as they were before or after the commit, but never
 * a mix of values.
 *
 * Clients call [get] to read a snapshot of an entry. The read will observe the value at the time
 * that [get] was called. Updates and removals after the call do not impact ongoing reads.
 *

// readFrom populates the content of the current file by reading from r.
// The bytes read must match the number of remaining bytes in the current file.
//
// If the current file is sparse and r is an io.ReadSeeker,
// then readFrom uses Seek to skip past holes defined in Header.SparseHoles,
// assuming that skipped regions are all NULs.
// This always reads the last byte to ensure r is the right size.
//

  }

  public void testOpenStream() throws IOException {
    Reader reader = source.openStream();

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;
    while ((read = reader.read(buf)) != -1) {
      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertExpectedString(writer.toString());
  }

}

func newCountUpReader(reader io.Reader) *countUpReader {
	return &countUpReader{
		reader: reader,
	}
}

type progressReader struct {
	rc              io.ReadCloser
	scannedReader   *countUpReader
	processedReader *countUpReader

	closedMu sync.Mutex
	closer   io.ReadCloser
	closed   bool
}

func (pr *progressReader) Read(p []byte) (n int, err error) {

     */
    public PersistedToolchains read(Reader reader) throws IOException, XmlPullParserException {
        return read(reader, true);
    }

    /**
     * Method read.
     *
     * @param in a in object.
     * @param strict a strict object.
     * @return PersistedToolchains
     * @throws IOException IOException if any.
     * @throws XmlPullParserException XmlPullParserException if
     *         any.

      }

      override fun fromDer(reader: DerReader): Any? {
        if (isOptional && !reader.hasNext()) return optionalValue

        val peekedHeader =
          reader.peekHeader()
            ?: throw ProtocolException("expected a value at $reader")
        for ((_, adapter) in choices) {
          if (adapter.matches(peekedHeader)) {
            return adapter.fromDer(reader)
          }
        }

type recordTransform struct {
	reader io.Reader
	// recordDelimiter can be up to 2 characters.
	recordDelimiter []byte
	oneByte         []byte
	useOneByte      bool
}

func (rr *recordTransform) Read(p []byte) (n int, err error) {
	if rr.useOneByte {
		p[0] = rr.oneByte[0]
		rr.useOneByte = false
		n, err = rr.reader.Read(p[1:])
		n++
	} else {
		n, err = rr.reader.Read(p)
	}

	if err != nil {

    }

    /**
     * Wraps exception handling for {@link Properties#load(Reader)}.
     * <p>
     * The input reader is not closed.
     * </p>
     *
     * @param props the property set (must not be {@literal null})
     * @param reader the input reader (must not be {@literal null})
     */
    public static void load(final Properties props, final Reader reader) {
        assertArgumentNotNull("props", props);

    }

    @Nonnull
    default T read(@Nonnull InputStream input, boolean strict) throws XmlReaderException {
        return read(XmlReaderRequest.builder().inputStream(input).strict(strict).build());
    }

    @Nonnull
    default T read(@Nonnull Reader reader) throws XmlReaderException {
        return read(reader, true);
    }

    @Nonnull

    /**
     * Reads setup data from wire format
     * @param buffer source buffer
     * @param bufferIndex starting index in source buffer
     * @param len length of data to read
     * @return number of bytes read
     */
    protected abstract int readSetupWireFormat(byte[] buffer, int bufferIndex, int len);

    /**
     * Reads parameters from wire format