'Change the symbol that is displayed by this symbol widget.
:type symbol: str
:param symbol: The name of the symbol to display.'

def set_symbol(self, symbol):

    if (symbol not in SymbolWidget.SYMBOLS):
        raise ValueError(('Unknown    symbol:    %s' % symbol))
    self._symbol = symbol
    self.set_text(SymbolWidget.SYMBOLS[symbol])
