Added stubs for AEvents
Added stubs for AEvents

liangcun/ConceptsOfSpatialInformation,spatial-ucsb/ConceptsOfSpatialInformation,liangcun/ConceptsOfSpatialInformation,spatial-ucsb/ConceptsOfSpatialInformation,spatial-ucsb/ConceptsOfSpatialInformation,liangcun/ConceptsOfSpatialInformation