public UsageExpression(UsageGraph parent, string description)
{
_parent = parent;
_commandUsage = new CommandUsage
{
Description = description,
Arguments = new Argument[0],
ValidFlags = _parent.Handlers.Where(x => !x.GetType().CanBeCastTo <Argument>()).ToArray() // Hokum.
};
_parent._usages.Add(_commandUsage);
}