human
Solve the following python programming problem given the following code:
def cost_getter(option_getter, costs_type = 'costs') : 
    def get_cost(cost, y, k, x = None) : 
        return option_getter (((((((y + '.') + costs_type) + '.') + k) + '.') + cost), default = ((((y + '.') + costs_type) + '.default.') + cost), x = x) 
return costs_type 

    
    

    Fix the buggy line: return costs_type
assistant
#Here is Python code to fix the buggy line: return costs_type
.

return def get_cost(