getEdgeProperty :: Key -> Id -> GS (Maybe Value)
getEdgeProperty k i = getEdgeByIdUnsafe i >>= getEdgePropertyE k
getEdgeProperty :: Key -> Id -> GS (Maybe Value)
getEdgeProperty k i = getEdgeByIdUnsafe i >>= getEdgePropertyE k
getEdgeProperty k i = getEdgeByIdUnsafe i >>= getEdgePropertyE k