in grafana/alert/condition.js [79:88]
function withReducer(type) {
const types = ['min', 'max', 'sum', 'avg', 'count', 'last', 'median', 'diff'];
if (!types.includes(type)) {
throw Error(`Reducer has to be one of [${types.toString()}]`);
}
that._reducer.type = type;
return this;
}