private async void BtnTimeAdd_Click(object sender, EventArgs e)
{
try {
if (!TimeSpan.TryParse(txtTime.Text, out TimeSpan times))
{
return;
}
await testManager.AddTime(times,
c => lvClients.SelectedItems.ContainsKey(c.Id.ToString()));
} catch (Exception ex) {
MessageBox.Show("Error sending command, error: " + ex.Message, "Error", MessageBoxButtons.OK,
MessageBoxIcon.Error);
}
}