public void SystemStringBuilderReplaceMany()
 {
     SystemSb.Replace("1618543976", "123");
     SystemSb.Replace("1813591724", "123");
     SystemSb.Replace("2018256345", "123");
 }
 public void SystemStringBuilderLargeAppendReplace()
 {
     SystemSb.Replace("2018256345", "123");
 }