Tree Grid does not work

Issue type

I’m submitting a … (check one with “x”)

• bug report
• [] feature request

Issue description

Current behavior:

The following exception is thrown while trying to integrate TreeGrid component by following example provided in documentation for the Data Source use This is html code at line referenced below in stack : at AllAnalyticsComponent_Template (all-analytics.component.html:5) <table [nbTreeGrid]="source"> Exception stack

TypeError: Cannot read property 'nativeElement' of null
    at new CdkTable (table.js:1265)
    at new NbTable (index.js:18425)
    at new NbTreeGridComponent (index.js:25275)
    at NodeInjectorFactory.NbTreeGridComponent_Factory [as factory] (index.js:25416)
    at getNodeInjectable (core.js:4029)
    at instantiateAllDirectives (core.js:7963)
    at createDirectivesInstances (core.js:7329)
    at Module.ɵɵelementStart (core.js:13901)
    at AllAnalyticsComponent_Template (all-analytics.component.html:5)
    at executeTemplate (core.js:7302)
    at resolvePromise (zone-evergreen.js:798)
    at resolvePromise (zone-evergreen.js:750)
    at zone-evergreen.js:860
    at ZoneDelegate.invokeTask (zone-evergreen.js:399)
    at Object.onInvokeTask (core.js:27424)
    at ZoneDelegate.invokeTask (zone-evergreen.js:398)
    at Zone.runTask (zone-evergreen.js:167)
    at drainMicroTaskQueue (zone-evergreen.js:569)
    at ZoneTask.invokeTask [as invoke] (zone-evergreen.js:484)
    at invokeTask (zone-evergreen.js:1621)

Expected behavior:

I would expect the TreeGrid to show up with no errors

Steps to reproduce:

Copy provided example and try to run

Related code:

see documentation code

Other information:

I am using Nebular v6 and Angular v1 npm, node, OS, Browser

<!--
Node, npm: `node --version` and `npm --version`
OS: Windows (7/8/10). Linux (incl. distribution). macOS (El Capitan? Sierra?)
Browser: Chrome/Safari/Firefox/etc?
-->

Angular, Nebular

   "@akveo/ng2-completer": "^9.0.1",
    "@angular/animations": "^10.0.11",
    "@angular/cdk": "^10.1.3",
    "@angular/common": "^10.0.11",
    "@angular/compiler": "^10.0.11",
    "@angular/core": "^10.0.11",
    "@angular/forms": "^10.0.11",
    "@angular/google-maps": "^9.1.0",
    "@angular/platform-browser": "^10.0.11",
    "@angular/platform-browser-dynamic": "^10.0.11",
    "@angular/router": "^10.0.11",
    "@asymmetrik/ngx-leaflet": "3.0.1",
    "@nebular/auth": "6.0.0",
    "@nebular/eva-icons": "6.0.0",
    "@nebular/security": "6.0.0",
    "@nebular/theme": "6.0.0",

[yggg]

There is a breaking change in the Angular CDK introduced in the patch update 10.1.2 (see issue in cdk repo for details). To fix the error downgrade to @angular/cdk@10.1.1. Once fix released you can upgrade to the latest version of cdk. Closing as unrelated to Nebular.

[sayax]

same issue