Optional
aInstancePtr: objectA run time mechanism for interface discovery.
NS_OK if the interface is supported by the associated instance, NS_NOINTERFACE if it is not.
aInstancePtr must not be null.
[in] A requested interface IID
[out] A pointer to an interface pointer to receive the result.
Generated using TypeDoc
This interface is only used in order to mark the fact that an object isn't a complete implementation of its interfaces. For example, a consumer can QI NullHttpChannel to nsINullChannel, to determine if the object is just a dummy implementation of nsIHttpChannel.