def __init__(self, cell_pattern=create_empty_grid()):
"""
Ctor - initialises the grid as a two-dimensional array of GoLCells.
@param cell_pattern If the cell pattern is given to this method as a parameter, it is used as the initial
cell configuration for the grid, otherwise, all the cells in the grid are set to dead.
"""
Grid.__init__(self, cell_pattern)
