code: def corner_extent(ul, ll, ur, lr): 
      
      xmin = min(ul[0], ll[0], ur[0], lr[0])
      xmax = max(ul[0], ll[0], ur[0], lr[0])
      ymin = min(ul[1], ll[1], ur[1], lr[1])
      ymax = max(ul[1], ll[1], ur[1], lr[1])
      extent = [xmin, ymin, xmax, ymax]
      return extent
docs: Get min/max extent based on corner coord