private void SetSymbol(IReadOnlyDictionary<string, string> rDict)
{
int symbol_no = this.GetIntPr(rDict, "symbol_no", 1),
symbol_size = this.GetIntPr(rDict, "symbol_size", 15),
symbol_color = this.GetIntPr(rDict, "symbol_color", 0);
MiApi.mitab_c_set_symbol(this.Handle, symbol_no, symbol_size, symbol_color);
}