def get_cleanup_hitters_unique(year)
      hitters = get_cleanup_hitters_by_year(year)
      h = {}
      hitters.each {|hitter| h[hitter.batter_name]=hitter}
      h.values
    end
def get_cleanup_hitters_unique(year)
      hitters = get_cleanup_hitters_by_year(year)
      h = {}
      hitters.each {|hitter| h[hitter.batter_name]=hitter}
      h.values
    end
Returns an array of all hitters who have hit in the cleanup spot (4) at least one game during the specified season