Why is Proof of Work, Proof of Stake associated with Consensus Mechanisms/Algorithms?

I’m trying to simulate a transaction on the public blockchain that invokes a contract’s method with certain parameters. Then I want to make a follow-up transaction with some other method call.

I figured that I can use call() function in the JavaScript console to invoke a method without actually publishing a real transaction, e.g:

var abi = [...]; var contractAddress = "0x..."; var contract = web3.eth.contract(abi).at(contractAddress); contract.updateSomething.call(...);    // change some values 

The problem now is: How can I make another call that uses the updated state of the contract?

If I just use another call() it returns the old value, not the updated one.

... contract.updateSomething.call(...);    // change some values contract.readSomething.call();         // returns old value