title: Why I cannot get props from the Provider by mobx-react
body: <p>I am tring to use the Mobx to manage my react-project's state,but I cannot get the props from the Provider by mobx-react.</p>
  
  <p>This is my root element(I delete the router to simplify the question):</p>
  
  <pre class="lang-js prettyprint-override"><code>import React from "react";
  import ReactDOM from "react-dom";
  import {Router, Route, hashHistory} from "react-router";
  import {Provider} from "mobx-react";
  
  import store from "../store";
  import App from "./app";
  
  ReactDOM.render((
      &lt;Provider store={store}&gt;
         &lt;App/&gt;
      &lt;/Provider&gt;),
    document.getElementById("content"));
  </code></pre>
  
  <p>and this is my childNode:</p>
  
  <pre class="lang-js prettyprint-override"><code>import React, {Component} from "react";
  import {observer, inject, PropTypes} from "mobx-react";
  
  @inject("store") @observer
  export default class App extends Component {
    constructor(props) {
      super(props);
  
      console.log(this.props.store);
    }
  
    render() {
      return (
        &lt;div&gt;
          ab
        &lt;/div&gt;
      )
    }
  }
  
  App.propTypes = {
    store: PropTypes.observableObject
  };
  </code></pre>
  
  <p>But when I log the store,the result is undefined, and I don't know why I cannot get the store.</p>
  
  <p>From the chrome devtools, I find the <strong>Provider has the store</strong> but App cannot get store,I am very confused.</p>
  
  <p>My store is bellow:</p>
  
  <pre class="lang-js prettyprint-override"><code>import {observable} from "mobx";
  class Store {
    @observable count;
  
    constructor() {
      this.count = 1;
    }
  
    addCount() {
      this.count += 1;
    }
  
    decreaseCount() {
      this.count -= 1;
    }
  }
  
  let store = new Store();
  
  export default store;
  </code></pre>