private void verbNetClasses_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            output2.Clear();

            if (verbNetClasses.SelectedIndex == -1)
            {
                return;
            }

            foreach (string example in SelectedVerbNetClass.GetExamples(false))
            {
                output2.AppendText(example + Environment.NewLine);
            }
        }
        private void verbNetClasses_SelectedIndexChanged(object sender, EventArgs e)
        {
            verbNetRoles.Items.Clear();

            if (verbNetClasses.SelectedIndex == -1)
            {
                return;
            }

            foreach (VerbNetEngine.ThematicRole role in SelectedVerbNetClass.GetThematicRoles(true))
            {
                verbNetRoles.Items.Add(role);
            }
        }