<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_field_values(self, name, maxvalues=-1, sort=True, **query_dict):
 """Retrieve the unique values for a field, along with their usage counts. :param name: Name of field for which to retrieve values :type name: string :param sort: Sort the result :param maxvalues: Maximum number of values to retrieve. Default is -1, which causes retrieval of all values. :type maxvalues: int """

        param_dict = query_dict.copy()
        param_dict.update(
            {
                'rows': '0',
                'facet': 'true',
                'facet.field': name,
                'facet.limit': str(maxvalues),
                'facet.zeros': 'false',
                'facet.sort': str(sort).lower(),
            }
        )
        resp_dict = self._post_query(**param_dict)
        result_dict = resp_dict['facet_counts']['facet_fields']
        result_dict['numFound'] = resp_dict['response']['numFound']
        return result_dict