Cannot resolve method Observable.from in rxjava 2 : <p>There is a from method in the Observable class in rxjava 1 but not found in rxjava 2. How can I replace the from method in rxjava 2 in the following code:</p>

<pre><code>    List&lt;Integer&gt; ints = new ArrayList&lt;&gt;();
    for (int i=1; i&lt;10; i++) {
        ints.add(new Integer(i));
    }
    Observable.just(ints)
            .flatMap(new Function&lt;List&lt;Integer&gt;, Observable&lt;Integer&gt;&gt;() {
                @Override
                public Observable&lt;Integer&gt; apply(List&lt;Integer&gt; ints) {
                    return Observable.from(ints);
                }
            })
</code></pre>
