public static string Clear(string id = "*")
{
if (String.IsNullOrWhiteSpace(id))
{
id = "*";
}
if (id.Equals("*"))
{
try {
foreach (Shell s in Shells.Values)
{
// if (!s.ShellId.Equals(ConsoleShellId))
s.Clear();
}
} catch (Exception) {
}
}
else
{
Shell s = GetShell(id);
if (s != null)
{
s.Clear();
}
}
return("");
}