@Override public String allowDeleteCategoryCombo( CategoryCombo categoryCombo ) { for ( Indicator indicator : indicatorService.getAllIndicators() ) { Set<CategoryOptionCombo> optionCombos = expressionService.getOptionCombosInExpression( indicator .getNumerator() ); optionCombos.retainAll( categoryCombo.getOptionCombos() ); if ( !optionCombos.isEmpty() ) { return indicator.getName(); } optionCombos = expressionService.getOptionCombosInExpression( indicator.getDenominator() ); optionCombos.retainAll( categoryCombo.getOptionCombos() ); if ( !optionCombos.isEmpty() ) { return indicator.getName(); } } return null; } }