// check multi-value flag
if (multipleValues != isMultiple()) {
String msg = (multipleValues) ?
"Single-valued property can not be set to an array of values:" :
"Multivalued property can not be set to a single value (an array of length one is OK): ";
throw new ValueFormatException(msg + this);
}
// check protected flag and for retention/hold
sessionContext.getItemValidator().checkModify(
this, CHECK_CONSTRAINTS, Permission.NONE);