@staticmethod<EOL><INDENT>def cross_successors(state, last_action=None):<DEDENT>
centres, edges = state<EOL>acts = sum([<EOL>[s, s.inverse(), s * <NUM_LIT:2>] for s in<EOL>map(Step, "<STR_LIT>".replace(last_action.face if last_action else "<STR_LIT>", "<STR_LIT>", <NUM_LIT:1>))<EOL>], [])<EOL>for step in acts:<EOL><INDENT>yield step, (centres, CrossSolver._rotate(edges, step))<EOL><DEDENT>
Successors function for solving the cross.