for Contract Without Spec
Create a ContractClient without loading the contract spec from the network.
Unlike forContract, this factory performs no RPC round-trip: it builds the client immediately. Because no ContractSpec is loaded, the Map-based invoke/buildInvoke overloads and the spec-backed conversion helpers (funcArgsToXdrSCValues, funcResToNative, ...) are unavailable and throw IllegalStateException; use the positional List<SCValXdr> overloads instead.
This is the construction path for generated bindings, which embed all contract type knowledge and therefore neither need the network spec nor the runtime conversion it enables. It also supports interacting with contracts whose spec is unavailable.
Return
ContractClient without a contract spec
Parameters
The contract ID (C... address)
The RPC server URL
The network (TESTNET/PUBLIC)