title: I install '@angular/cdk' and got an error when I import DragDropModule, what do I do wrong?
body: <p><strong>What are you trying to do?</strong></p>
  
  <p>I want to use <code>@angular/cdk</code> (<a href="https://www.npmjs.com/package/@angular/cdk" rel="nofollow noreferrer">source</a>) to make a modal draggable as seen in their <a href="https://material.angular.io/cdk/drag-drop/overview" rel="nofollow noreferrer">tutorial</a></p>
  
  <p><strong>Reproduction</strong></p>
  
  <p><code>npm i @angular/cdk</code></p>
  
  <p>then when I import the module in my file xxx.module.ts : </p>
  
  <p><code>import { DragDropModule } from '@angular/cdk/drag-drop';</code></p>
  
  <p>I immediately obtain a list of error messages : </p>
  
  <blockquote>
  <pre><code>ERROR in node_modules/@angular/cdk/bidi/dir.d.ts(26,9): error TS1086: An accessor cannot be declared in an ambient context.
  </code></pre>
  </blockquote>
  
  <p><a href="https://i.stack.imgur.com/oTzov.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oTzov.png" alt="error console"></a></p>
  
  <p><strong>Environment</strong></p>
  
  <p>Here is my <code>package.json</code> :</p>
  
  <pre><code>{
    "name": "libertchan",
    "version": "0.0.0",
    "scripts": {
      "ng": "ng",
      "start": "ng serve",
      "build": "ng build",
      "test": "ng test",
      "lint": "ng lint",
      "e2e": "ng e2e"
    },
    "private": true,
    "dependencies": {
      "@angular/animations": "~8.2.14",
      "@angular/cdk": "^9.0.0",
      "@angular/common": "~8.2.14",
      "@angular/compiler": "~8.2.14",
      "@angular/core": "~8.2.14",
      "@angular/forms": "~8.2.14",
      "@angular/platform-browser": "~8.2.14",
      "@angular/platform-browser-dynamic": "~8.2.14",
      "@angular/router": "~8.2.14",
      "@ng-bootstrap/ng-bootstrap": "^5.2.1",
      "bootstrap": "^4.4.1",
      "rxjs": "~6.4.0",
      "tslib": "^1.10.0",
      "zone.js": "~0.9.1"
    },
    "devDependencies": {
      "@angular-devkit/build-angular": "~0.803.19",
      "@angular/cli": "~8.3.19",
      "@angular/compiler-cli": "~8.2.14",
      "@angular/language-service": "~8.2.14",
      "@types/node": "~8.9.4",
      "@types/jasmine": "~3.3.8",
      "@types/jasminewd2": "~2.0.3",
      "codelyzer": "^5.0.0",
      "jasmine-core": "~3.4.0",
      "jasmine-spec-reporter": "~4.2.1",
      "karma": "~4.1.0",
      "karma-chrome-launcher": "~2.2.0",
      "karma-coverage-istanbul-reporter": "~2.0.1",
      "karma-jasmine": "~2.0.1",
      "karma-jasmine-html-reporter": "^1.4.0",
      "protractor": "~5.4.0",
      "ts-node": "~7.0.0",
      "tslint": "~5.15.0",
      "typescript": "~3.5.3"
    }
  }
  </code></pre>