async def _clear_database(self):
    cursor = (await self.db_connection.execute('DELETE FROM puzzle_hashes'))
    (await cursor.close())
    cursor = (await self.db_connection.execute('DELETE FROM interested_coins'))
    (await cursor.close())
    (await self.db_connection.commit())
async def _clear_database(self):
    cursor = (await self.db_connection.execute('DELETE FROM puzzle_hashes'))
    (await cursor.close())
    cursor = (await self.db_connection.execute('DELETE FROM interested_coins'))
    (await cursor.close())
    (await self.db_connection.commit())