@Override
	public BigInteger getIndexBefore(BigInteger index) {
		if (index.compareTo(BigInteger.ZERO) <= 0) {
			return null;
		}
		return index.subtract(BigInteger.ONE);
	}
Control the GUI layout for displaying tokenized C code
Ghidra/Features/Decompiler/src/main/java/ghidra/app/decompiler/component/ClangLayoutController.java