private void addRegisterAndValue(String register, BigInteger value) {
		if (!contextRegisters.contains(register)) {
			contextRegisters.add(register);
			Set<BigInteger> valueSet = new HashSet<BigInteger>();
			regsToValues.put(register, valueSet);
		}
		regsToValues.get(register).add(value);
	}
Accumulates the information in each element of {@code contextRegisterInfo} into the extent.
@param contextRegisterInfo
Ghidra/Features/BytePatterns/src/main/java/ghidra/bitpatterns/info/ContextRegisterExtent.java