private int getValueOrdinal(GTableCellRenderingData data) {
			Boolean booleanValue = (Boolean) data.getValue();

			return booleanValue == null ? 0 : booleanValue.booleanValue() ? 2 : 1;
		}
Table column renderer to render a boolean value as an icon
Ghidra/Features/PDB/src/main/java/pdb/symbolserver/ui/SymbolFileTableModel.java