Using the modifiers every ethereum-client will tell the caller, during the local evaluation (not yet broadcasting it to the network), "Hey if you call this method it will fail, please don't waste the transaction costs for a failing transaction". Until now the call led to a transaction that did nothing but was still broadcasted and required transaction fees.
Using the modifiers every ethereum-client will tell the caller, during the local evaluation (not yet broadcasting it to the network), "Hey if you call this method it will fail, please don't waste the transaction costs for a failing transaction". Until now the call led to a transaction that did nothing but was still broadcasted and required transaction fees.