Patch the return time with MaxInt64 in robustness test

Reference:
- #19579

Signed-off-by: Chun-Hung Tseng <[email protected]>

Author: henrybear327

tests/robustness/model/history.go

@@ -16,6 +16,7 @@ package model
 
 import (
 	"fmt"
+	"math"
 	"strings"
 	"time"
 
@@ -488,36 +489,17 @@ func (h History) Len() int {
 
 func (h History) Operations() []porcupine.Operation {
 	operations := make([]porcupine.Operation, 0, len(h.operations))
-	maxTime := h.lastObservedTime()
 	for _, op := range h.operations {
 		// Failed requests don't have a known return time.
 		if op.Return == -1 {
-			// Simulate Infinity by using last observed time.
-			op.Return = maxTime + time.Second.Nanoseconds()
+			// Simulate infinity for failed requests
+			op.Return = math.MaxInt64
 		}
 		operations = append(operations, op)
 	}
 	return operations
 }
 
-func (h History) lastObservedTime() int64 {
-	var maxTime int64
-	for _, op := range h.operations {
-		if op.Return == -1 {
-			// Collect call time from failed operations
-			if op.Call > maxTime {
-				maxTime = op.Call
-			}
-		} else {
-			// Collect return time from successful operations
-			if op.Return > maxTime {
-				maxTime = op.Return
-			}
-		}
-	}
-	return maxTime
-}
-
 func (h History) MaxRevision() int64 {
 	var maxRevision int64
 	for _, op := range h.operations {