title: Relational pouch methods aren't available in Angular Service
body: <p>I'm trying to get relational-pouch working, I'm able to set the schema but when I call the save function I get the error <code>TypeError: this.rel.save is not a function</code></p>
  <p>This is the setup:</p>
  <pre><code>import PouchDB from 'pouchdb-browser'
  import find from 'pouchdb-find'
  import rel from 'relational-pouch'
  
  @Injectable({
      providedIn: 'root'
  })
  export class PouchDBService {
  
      public base_db: PouchDB.Database
      public rel
  
      constructor() {
          PouchDB.plugin(find)
          PouchDB.plugin(rel)
          this.base_db = new PouchDB('Eeeek')
          this.rel = this.base_db.setSchema(schema)
          this.rel.save('project', {
              name: 'George R. R. Martin', id: 1, books: [6, 7]
          })
      }
  }
  </code></pre>
  <p>When I try to call <code>this.rel.find(id)</code> it seems to be ignoring the <em>relational-pouch</em> definition and using the <em>pouch-find</em> definition. So <code>this.rel.find(id)</code> results in <code>Error: you must provide search parameters to find()</code></p>
  <p>but</p>
  <pre><code>            this.db.rel.find({
                  selector: {
                      type: this.type
                  }
              })
  </code></pre>
  <p>works.</p>
  <p>The dependencies seem fine, I'm stumped, any help greatly appreciated.</p>
  <p>Thanks.</p>
  <p>ps. using angular 12.</p>