Given the following data structure for different vector feature types,
#MultiPoint
pts = [(3,4), (8,2), (6,5), (3,9), (7,15)]
#MultiLine
lines = [[(1,1), (4,5), (1,6)], [(8,2), (2,8)], [(1,3), (5,3), (8,3)]]
#Polygon
poly = [[(2,1), (4,1), (3,3), (2,1)]]
#Polygon with holes
poly2 = [[(8,1), (5,1), (5,4), (8,4), (8,1)], [(6,2), (7,2), (7,3), (6,2)]]
#MultiPolygon
polys = [poly, poly2]
Write a command to extract the main ring from each polygon in polys, and write these main rings to a new Multipolygon structure (that is, remove any holes) as a new variable called newpolys.