public abstract class SIPExtensionWrapper : ISIPExtension, 
	IPBXSIPClient, IExtensionBase, IUserAgentInstance, ISIPClientCommon

Public MustInherit Class SIPExtensionWrapper
	Implements ISIPExtension, IPBXSIPClient, IExtensionBase, IUserAgentInstance, 
	ISIPClientCommon

public ref class SIPExtensionWrapper abstract : ISIPExtension, 
	IPBXSIPClient, IExtensionBase, IUserAgentInstance, ISIPClientCommon

[<AbstractClassAttribute>]
type SIPExtensionWrapper =  
    class
        interface ISIPExtension
        interface IPBXSIPClient
        interface IExtensionBase
        interface IUserAgentInstance
        interface ISIPClientCommon
    end