public int getVersion() {
		if (historyPanel != null && !usingOpenProgramList()) {
			return historyPanel.getSelectedVersionNumber();
		}
		return -1;
	}
Return the selected version number from the history panel.
@return -1 if a version history was not selected
Ghidra/Features/Base/src/main/java/ghidra/framework/main/OpenVersionedFileDialog.java