message: mock the catalog api
diff: @@ -39,6 +39,45 @@ import { HomePageStackOverflowQuestions } from '@backstage/plugin-stack-overflow
  import { Grid, makeStyles } from '@material-ui/core';
  import React, { ComponentType } from 'react';
  +const entities = [
  + {
  + apiVersion: '1',
  + kind: 'Component',
  + metadata: {
  + name: 'mock-starred-entity',
  + title: 'Mock Starred Entity!',
  + },
  + },
  + {
  + apiVersion: '1',
  + kind: 'Component',
  + metadata: {
  + name: 'mock-starred-entity-2',
  + title: 'Mock Starred Entity 2!',
  + },
  + },
  + {
  + apiVersion: '1',
  + kind: 'Component',
  + metadata: {
  + name: 'mock-starred-entity-3',
  + title: 'Mock Starred Entity 3!',
  + },
  + },
  + {
  + apiVersion: '1',
  + kind: 'Component',
  + metadata: {
  + name: 'mock-starred-entity-4',
  + title: 'Mock Starred Entity 4!',
  + },
  + },
  +];
  +
  +const mockCatalogApi = {
  + getEntities: async () => ({ items: entities }),
  +};
  +
  const starredEntitiesApi = new MockStarredEntitiesApi();
  starredEntitiesApi.toggleStarred('component:default/example-starred-entity');
  starredEntitiesApi.toggleStarred('component:default/example-starred-entity-2');
  @@ -53,6 +92,7 @@ export default {
  <>
  <TestApiProvider
  apis={[
  + [catalogApiRef, mockCatalogApi],
  [starredEntitiesApiRef, starredEntitiesApi],
  [searchApiRef, { query: () => Promise.resolve({ results: [] }) }],
  [
  