title: Unresolved reference: query　（Android Kotlin)
body: <p>Thanks for read this question.
  I'm new to Android development.</p>
  <p>In my project,I'm trying to access video file in shared storage.</p>
  <p>To accomplished the purpose,I wrote the below code.
  In the code, ContentResolver's query method is unresolved.I don't understand why.</p>
  <pre><code> val query = ContentResolver.query( &lt;-Unresolved
          collection,
          projection,
          selection,
          selectionArgs,
          sortOrder
      )
      query?.use{
          cursor -&gt;
          val idColumn = cursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID)
          val nameColumn = cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DISPLAY_NAME)
          val durationColumn = cursor.getColumnIndexOrThrow(MediaStore.Video.Media.SIZE)
          while(cursor.movieToNext()){
              val id = cursor.getLong(idColumn)
              val name = cursor.getString(nameColumn)
              val duration = cursor.getInt(durationColumn)
              val size = cursor.getInt(sizeColumn)
  
              val contentUri: Uri = ContentUris.withAppendedId(
                  MediaStore.Video.Media.EXTERNAL_CONTENT_URI,
                  id)
              videoList += Video(contentUri, name, duration, size)
          }
  </code></pre>
  <p>So coule someone please explaine to me the reason.Thank you.</p>