defect
Formatting null should return null, no exception:
Caused by: java.lang.IllegalArgumentException: Cannot format given Object as a Number at java.base/java.text.DecimalFormat.format(DecimalFormat.java:515) at java.base/java.text.Format.format(Format.java:159) at com.top_logic.model.search.expr.FormatExpr.eval(FormatExpr.java:58) at com.top_logic.model.search.expr.GenericMethod.internalEval(GenericMethod.java:87) at com.top_logic.model.search.expr.SearchExpression.evalWith(SearchExpression.java:112) ... 168 more