'Returns the address of the wallet with a specific identifier. Raises a ValueError if that wallet is not
available.'

def get_wallet_address(self, wallet_id):

    if ((wallet_id not in self.wallets) or (not self.wallets[wallet_id].created)):
        raise ValueError(('Wallet    %s    not    available' % wallet_id))
    return self.wallets[wallet_id].get_address()
