@Override
	public boolean isClosed() {
		return szBPStream == null;
	}
Opens the specified sevenzip container file and initializes this file system with the
contents.

@param byteProvider container file 
@param monitor {@link TaskMonitor} to allow the user to monitor and cancel
@throws CancelledException if user cancels
@throws IOException if error when reading data
Ghidra/Features/FileFormats/src/main/java/ghidra/file/formats/sevenzip/SevenZipFileSystem.java