code: def area(poly):
      
      poly_area = 0
      # TODO: polygon holes at coordinates[1]
      points = poly['coordinates'][0]
      j = len(points) - 1
      count = len(points)
  
      for i in range(0, count):
          p1_x = points[i][1]
          p1_y = points[i][0]
          p2_x = points[j][1]
          p2_y = points[j][0]
  
          poly_area += p1_x * p2_y
          poly_area -= p1_y * p2_x
          j = i
  
      poly_area /= 2
      return poly_area
docs: calculate the area of polygon
  
      Keyword arguments:
      poly -- polygon geojson object
  
      return polygon area