# Reducer
Defines a reducer against your model.
# API
Reducer<
  State = any, 
  Action extends ReduxAction = ReduxAction
>
- State- The type for the state that will be managed by the reducer. 
- Action- The type of the actions that may be received by the reducer. 
# Example
import { Reducer, reducer } from 'easy-peasy';
interface StoreModel {
  todos: Reducer<string[]>;
}
const storeModel: StoreModel = {
  todos: reducer((state = [], action) => {
    switch (action.type) {
      case 'ADD_TODO': return [...state, action.payload];
      default: return state;
    }
  })
}