title: The method 'getDocuments' isn't defined for the type 'CollectionReference'
body: <pre><code>   FirebaseFirestore.instance.collection('locations').getDocuments().then((docs){
        if(docs.documents.isNotEmpty){
          for(int i=0 ;i&lt;docs.documents.length;i++){
              initMarker(docs.documents[i].data , docs.documents[i].documentID);
          }
        }
      });
    }
  </code></pre>
  <p>init Marker Snap</p>
  <pre><code>void initMarker(request,requestId){
    var markerIdVal = requestId;
    final MarkerId markerId = MarkerId(markerIdVal);
    //creating a new Marker
    final Marker marker = Marker(
      markerId:markerId,
      position:LatLng(request['loc_Coords'].lattitude,request['loc_Coords'].longitude),
      infoWindow:InfoWindow(
        title:request['loc_Name'],
        snippet:request['loc_Description'],
      ),
      );
    setState((){
      markers[markerId] = marker;
      print(markerId);
    });
  </code></pre>
  <p><strong>The method 'getDocuments' isn't defined for the type 'CollectionReference'.</strong></p>
  <p>Please could you help me to get rid this error?</p>