question: void initDemandAndCollectionMap ( final List < String > prepareFieldNames , final Map < String , BigDecimal > demand , final Map < String , BigDecimal > collection , final Map < String , BigDecimal > rebates ) { if ( prepareFieldNames != null && ! prepareFieldNames . isEmpty ( ) ) for ( final String fieldName : prepareFieldNames ) { demand . put ( fieldName , BigDecimal . ZERO ) ; collection . put ( fieldName , BigDecimal . ZERO ) ; rebates . put ( fieldName , BigDecimal . ZERO ) ; } }
target:  Method called internally to prepare the Map with fieldNames dynamically(i.e field names can be verified depending upon the client)