public byte readByte() throws IOException {
		checkOpen();
		ensure(1);
		return buffer[(int) bufferOffset];
	}
This method reads a byte from the file, starting from the current file pointer. 
<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 file as a signed eight-bit
            <code>byte</code>.
@exception  EOFException  if this file has reached the end.
@exception  IOException   if an I/O error occurs.
GPL/DMG/src/dmg/java/mobiledevices/dmg/ghidra/GRandomAccessFile.java