@Override
		public void setPropertyChanged(String propertyName, Address codeUnitAddr, Object oldValue,
				Object newValue) {
			changed = true;
			program.userDataChanged(propertyName, codeUnitAddr, oldValue, newValue);
		}
UPGRADE_REQUIRED_BFORE_VERSION should be changed to DB_VERSION any time the
latest version requires a forced upgrade (i.e., Read-only mode not supported
until upgrade is performed).  It is assumed that read-only mode is supported
if the data's version is &gt;= UPGRADE_REQUIRED_BEFORE_VERSION and &lt;= DB_VERSION.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramUserDataDB.java