ICallingContext
Represents information about the web context from which the event handler is
            being called, such as the layout or page mode.
            
                
Gets or set a  ILayout containing
            the GUIDs and artifact ID of the layout associated with a call to an event handler.
            
Gets or sets the information needed by the event handler about the step in the
            page workflow associated with a call, such as a layout, list, edit, or other
            
Gets or sets a string indicating where the call to the event handler originates.