public final int readUnsignedByte() throws IOException {
        int ch = this.read();
        if (ch < 0)
            throw new EOFException();
        return ch;
    }
Reads an unsigned eight-bit number from this stream. This method reads
a byte from this stream, starting at the current stream pointer,
and returns that byte.
<p>
This method blocks until the byte is read, the end of the stream
is detected, or an exception is thrown.

@return     the next byte of this stream, interpreted as an unsigned
            eight-bit number.
@exception  EOFException  if this stream has reached the end.
@exception  IOException   if an I/O error occurs.
plugins/svg-plugin/batik-codec-fix/src/main/java/org/apache/batik/ext/awt/image/codec/util/SeekableStream.java