public synchronized DBBuffer getBuffer(int id) throws IOException {
		checkIsClosed();
		return new DBBuffer(this, new ChainedBuffer(bufferMgr, id));
	}
Get an existing buffer.  This method should be used with care to avoid 
providing an improper id.  A database transaction must be in progress
when invoking the various put, delete and setSize methods on the returned buffer.
@param id the buffer id.
@return Buffer the buffer associated with the given id.
@throws IOException if an I/O error occurs while getting the buffer.
Ghidra/Framework/DB/src/main/java/db/DBHandle.java