public boolean setGroup(String registerName, String groupName) {
		Register register = registerMap.get(registerName);
		if (register == null) {
			return false;
		}
		register.setGroup(groupName);
		return true;
	}
Set the group name for the specified register
@param registerName register name
@param groupName group name
@return true if register was found, else false
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/lang/RegisterBuilder.java