old_contents: import React from 'react'
  import User from '../components/user'
  
  class UseContainer extends React.Component {
    
    constructor(){
      super();
      this._getData = this._getData.bind(this); 
      this.state = {
        userName:'',
      }
    }
    _getData() {
      $.ajax({
        url:`/api/profile/${currentUser}`
      })
      .then(function(data) {
        data = data[0];
        this.setState({
          userName:data.username
        });
        console.log(data);
      }.bind(this)); 
    }
  
    componentDidMount() {
      this._getData();
    }
  
    render() {
      return (
        <User userName={this.state.userName} />
      )
    }
  }
  
  export default UseContainer;
new_contents: import React from 'react'
  import User from '../components/user'
  
  class UseContainer extends React.Component {
    
    constructor(){
      super();
      this._getData = this._getData.bind(this); 
      this.state = {
        userName:'',
      }
    }
    _getData() {
      $.ajax({
        url:`/api/profile/${currentUser}`
      })
      .then(function(data) {
        this.setState({
          userName:data.username
        });
        console.log(data);
      }.bind(this)); 
    }
  
    componentDidMount() {
      this._getData();
    }
  
    render() {
      return (
        <User userName={this.state.userName} />
      )
    }
  }
  
  export default UseContainer;
subject: test for username