title: remove streamBuilder loading widget
body: <p>I get data from the cache. When clicking the search button showing <code>RefreshProgressIndicator</code> and then showing <code>material_search</code> page. Is it possible to remove loading on <code>if(snapshot.hasdata){}else{loading widget}</code> without <code>null</code> error message? <em>If it is impossible, then how to use 'StreamBuilder' inside 'MaterialSerach' page?</em> I used MaterialSearch plugin.</p>
  
  <pre><code>builder: (BuildContext context) {
    return Material(
      child: StreamBuilder(
          stream: _subCategoryBloc.subCategory,
          builder: (context, AsyncSnapshot&lt;List&lt;SubCategorie&gt;&gt; snapshot) {
            if (snapshot.data != null) {
              return MaterialSearch&lt;String&gt;(
                barBackgroundColor: Color(0xFFEDB111),
                placeholder: 'Search',
                results: snapshot.data
                    .map((value) =&gt; MaterialSearchResult&lt;String&gt;(
                        value: value.subCategoryName,
                        subText: "${value.noOfMembers} Vendors",
                        categoryId: value.categoryId,
                        categoryName: value.categoryName,
                        subId: value.id,
                        text: value.subCategoryName))
                    .toList(),
                filter: (dynamic value, String criteria) {
                  return value.toLowerCase().trim().contains(
                      RegExp(r'' + criteria.toLowerCase().trim() + ''));
                },
                onSubmit: (String value) {
                  Navigator.of(context).pop(value);
                },
              );
            } else {
              return Center(
                  child: RefreshProgressIndicator(
                      backgroundColor: Color(0xFFFFFFFF)));
            }
          }),
    );
  });
  </code></pre>