if (context == null)
context = new TPreptimeContext(operandInstances, queryContext);
expression.setPreptimeContext(context);
if (castSource == null) {
castTo = null;
resultInstance = overloadResultStrategy.customRule().resultInstance(operandValues, context);
}
else {
castTo = overloadResultStrategy.customRule().resultInstance(operandValues, context);
resultInstance = castSource;
}