FROM:
        {
            "id": "60411677",
            "uri": "https://api.cityverve.org.uk/v1/entity/crime/60411677",
            "type": "crime",
            "name": "Anti Social Behaviour - On or near Manor Road",
            "loc": {},
            "entity": {
                "category": "Anti Social Behaviour",
                "occurred": "2017-10-01",
                "area": "On or near Manor Road",
                "outcome": {
                    "status": null,
                    "resolved": null
                }
            },
            "instance": {...},
            "legal": [..]
        }, {}, {}, ...

        TO:
        {
            "time": "2017-10-01",
            "value": "556"
        },
        {...}, {...}, ...

def get_children_as_time_series(self, json_children, time_field=['entity','occurred']):
        result = []
        time_field_as_path_list = time_field.strip().split(".")
        if len(time_field_as_path_list) == 0:
            return result

        """
        FROM:
        {
            "id": "60411677",
            "uri": "https://api.cityverve.org.uk/v1/entity/crime/60411677",
            "type": "crime",
            "name": "Anti Social Behaviour - On or near Manor Road",
            "loc": {},
            "entity": {
                "category": "Anti Social Behaviour",
                "occurred": "2017-10-01",
                "area": "On or near Manor Road",
                "outcome": {
                    "status": null,
                    "resolved": null
                }
            },
            "instance": {...},
            "legal": [..]
        }, {}, {}, ...

        TO:
        {
            "time": "2017-10-01",
            "value": "556"
        },
        {...}, {...}, ..."""

        # get times
        result_dict = {}
        for child in json_children:
            time = self.get_time(child[0], time_field_as_path_list)
            if time in result_dict:
                result_dict[time] += 1
            else:
                result_dict[time] = 1

        # turn lookup dict (result_dict) into final list
        for key, value in result_dict.items():
            temp = {'time': key, 'value': value}
            result.append(temp)

        return result