using System.Runtime.Serialization; namespace System { public class TimeZoneNotFoundException : Exception { public TimeZoneNotFoundException(); protected TimeZoneNotFoundException(SerializationInfo info, StreamingContext context); public TimeZoneNotFoundException(string message); public TimeZoneNotFoundException(string message, Exception innerException); } } namespace System { public class OverflowException : ArithmeticException { public OverflowException(); protected OverflowException(SerializationInfo info, StreamingContext context); public OverflowException(string message); public OverflowException(string message, Exception innerException); } }