src/test/java/com/android/volley/mock/ShadowSystemClock.java

package com.android.volley.mock;

import android.os.SystemClock;
import org.robolectric.annotation.Implements;

@Implements(value = SystemClock.class, callThroughByDefault = true)
public class ShadowSystemClock {
    public static long elapsedRealtime() {
        return 0;
    }
}