code: @Override
  	// @NotThreadSafe
  	public void put(long position, byte value) throws IOException {
  		int bufferNum = getBufferNum(position);
  		mappedBuffers.get(bufferNum).put(getIndex(position), value);
  		if(modifiedBuffers!=null) modifiedBuffers.set(bufferNum, true);
  	}
docs: Puts a single byte in the buffer.