Update stub to support batch calls.

op-challenger/game/fault/contracts/faultdisputegame_test.go

@@ -161,7 +161,7 @@ func setup(t *testing.T) (*test.AbiBasedRpc, *FaultDisputeGameContract) {
 	address := common.HexToAddress("0x24112842371dFC380576ebb09Ae16Cb6B6caD7CB")
 
 	stubRpc := test.NewAbiBasedRpc(t, fdgAbi, address)
-	caller := batching.NewMultiCaller(stubRpc, 1)
+	caller := batching.NewMultiCaller(stubRpc, 100)
 	game, err := NewFaultDisputeGameContract(address, caller)
 	require.NoError(t, err)
 	return stubRpc, game

op-service/sources/batching/test/stubs.go

@@ -3,6 +3,7 @@ package test
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"testing"
 
@@ -59,8 +60,13 @@ func (l *AbiBasedRpc) SetResponse(method string, expected []interface{}, output
 	})
 }
 
-func (l *AbiBasedRpc) BatchCallContext(_ context.Context, b []rpc.BatchElem) error {
-	panic("Not implemented")
+func (l *AbiBasedRpc) BatchCallContext(ctx context.Context, b []rpc.BatchElem) error {
+	var errs []error
+	for _, elem := range b {
+		elem.Error = l.CallContext(ctx, elem.Result, elem.Method, elem.Args...)
+		errs = append(errs, elem.Error)
+	}
+	return errors.Join(errs...)
 }
 
 func (l *AbiBasedRpc) CallContext(_ context.Context, out interface{}, method string, args ...interface{}) error {