protected BigInteger getLockedLineForPanel(FieldPanel fp) {
		for (int i = 0; i < lockedLineNumbers.length; i++) {
			if (panels[i] == fp) {
				return lockedLineNumbers[i];
			}
		}
		return null;
	}
Gets the locked line value for the indicated panel.
@param fp the field panel whose locked line value is wanted.
@return the locked line value or null if the panel isn't found.
Ghidra/Framework/Docking/src/main/java/docking/widgets/fieldpanel/internal/LineLockedFieldPanelCoordinator.java