finds spike containers in a multi spike containers collection

def find(self,cell_designation,cell_filter=lambda x,c: 'c' in x and x['c'] == c):
        """
            finds spike containers in a multi spike containers collection
        """
        res = [i for i,sc in enumerate(self.spike_containers) if cell_filter(sc.meta,cell_designation)]
        if len(res) > 0:
            return res[0]