fix bug in CAFeature (missing library import)
fix bug in CAFeature (missing library import)

thekingofkings/chicago-crime,thekingofkings/urban-flow-analysis,thekingofkings/chicago-crime,thekingofkings/urban-flow-analysis,thekingofkings/urban-flow-analysis,thekingofkings/chicago-crime,thekingofkings/urban-flow-analysis,thekingofkings/chicago-crime,thekingofkings/urban-flow-analysis,thekingofkings/chicago-crime,thekingofkings/chicago-crime