Backtrader EMA Crossover Trend Following Strategy

import backtrader as bt

class EMATrendFollowing(bt.Strategy):
    params = (('fast', 12), ('slow', 26))

    def __init__(self):
        self.ema_fast = bt.indicators.EMA(self.data.close, period=self.p.fast)
        self.ema_slow = bt.indicators.EMA(self.data.close, period=self.p.slow)
        self.crossover = bt.indicators.CrossOver(self.ema_fast, self.ema_slow)

    def next(self):
        if self.crossover > 0:  # Fast EMA crosses above slow EMA
            self.buy()
        elif self.crossover < 0:  # Fast EMA crosses below slow EMA
            self.sell()