title: Angular - Unexpected value MatDialog imported by the module AppModule
body: <p>I am trying to integrate Angular Material in Angular but getting following error. The program is compiled successfully but getting this issue in browser.</p>
  
  <pre><code>Uncaught Error: Unexpected value 'MatDialog' imported by the module 'AppModule'. Please add a @NgModule annotation.
      at syntaxError (compiler.js:485)
      at eval (compiler.js:15226)
      at Array.forEach (&lt;anonymous&gt;)
      at CompileMetadataResolver.getNgModuleMetadata (compiler.js:15201)
      at JitCompiler._loadModules (compiler.js:34385)
      at JitCompiler._compileModuleAndComponents (compiler.js:34346)
      at JitCompiler.compileModuleAsync (compiler.js:34240)
      at CompilerImpl.compileModuleAsync (platform-browser-dynamic.js:239)
      at PlatformRef.bootstrapModule (core.js:5551)
      at eval (main.ts:11)
  </code></pre>