public void Error_AlreadyOccurs (ResolveContext ec, TypeSpec switch_type, SwitchLabel collision_with)
{
string label;
if (converted == null)
label = "default";
else if (converted == NullStringCase)
label = "null";
else
label = converted.ToString ();
ec.Report.SymbolRelatedToPreviousError (collision_with.loc, null);
ec.Report.Error (152, loc, "The label `case {0}:' already occurs in this switch statement", label);
}