• Precondition?

Question related to mission Moore Neighbourhood

 

Precondition: 3 ≤ len(grid) ≤ 10 all(len(grid[0]) == len(row) for row in grid)

So does this means that all grids would have equal number of rows and columns?

I'm confused cause there's one test in check that has 6 rows and 5 columns...