old_contents: 'use strict';
  
  import Text from './Text';
  import Insert from './Insert';
  import Delete from './Delete';
  
  // editor content per user
  export default class Content {
    constructor(user) {
      this.user = user;
      this.id = 0; // current available id for each Chr obj
      this.text = Text();
    }
  
    // apply an inner-replica operation
    apply(loc, type, ch) {
      if (type === 'ins') {
        let chr = new Chr(this.user, ch, this.id);
        this.text.add(loc, chr);
        this.id = this.text.len();
      } else {
        this.text.remove(loc);
      }
    }
  
    // apply an inter-replica insert
    insert(ins) {
      this.text.addAfter(ins.preChrId, ins.chr);
      this.id = this.text.length();
    }
  
    // apply an inter-replica Delete
    delete(del) {
      this.text.removeAt(del.chrId);
    }
  
    toString() {
      return this.text.toString();
    }
  }
  
new_contents: 'use strict';
  
  import Text from './Text';
  import Insert from './Insert';
  import Delete from './Delete';
  
  // editor content per user
  export default class Content {
    constructor(user) {
      this.user = user;
      this.id = 0; // current available id for each Chr obj
      this.text = new Text();
    }
  
    // apply an inner-replica operation
    apply(loc, type, ch) {
      if (type === 'ins') {
        let chr = new Chr(this.user, ch, this.id);
        this.text.add(loc, chr);
        this.id = this.text.len();
      } else {
        this.text.remove(loc);
      }
    }
  
    // apply an inter-replica insert
    insert(ins) {
      this.text.addAfter(ins.preChrId, ins.chr);
      this.id = this.text.length();
    }
  
    // apply an inter-replica Delete
    delete(del) {
      this.text.removeAt(del.chrId);
    }
  
    toString() {
      return this.text.toString();
    }
  }
  
subject: Fix typo