@Override
	public BufferFile getNextChangeDataFile(boolean getFirst) throws IOException {
		if (bfMgr == null) {
			return null;
		}
		if (getFirst || nextChangeDataVer == -1) {
			nextChangeDataVer = minChangeDataVer != -1 ? minChangeDataVer : (version - 1);
		}
		if (nextChangeDataVer >= version) {
			return null;
		}
		File changedDataFile = bfMgr.getChangeDataFile(nextChangeDataVer++);
		if (changedDataFile != null && (minChangeDataVer != -1 || changedDataFile.exists())) {
			return new LocalBufferFile(changedDataFile, true);
		}
		return null;
	}
Create a new empty file for pre-save use.
@param presaveFile pre-save file
@param bufferSize buffer size
@throws IOException if an I/O error occurs during file creation
Ghidra/Framework/DB/src/main/java/db/buffers/LocalManagedBufferFile.java