title: Operator in class initialization?
body: <p>I've coded in Python about year and more, but today for the first time I saw something like this:</p>
  <pre><code>class ObjectSelector(bpy.types.Operator):
       bl_idname = &quot;lod.search&quot;
       bl_label = &quot;Search lod&quot;
       bl_options = {'REGISTER', 'UNDO'}
  
       searchKey: bpy.props.StringProperty(
            name=&quot;Search&quot;,
       )
  </code></pre>
  <p>This is code from Blender python plugin, and I want to ask what is <code>searchKey</code> in this case, because <code>bl_idname</code> is variable of class, but what in the world is <code>searchKey</code> and how even is this thing is called? Is it something like javascript class creation: <code>const tmp = {searchKey: &quot;&quot;}</code>?</p>