How to use the pywaves.DEFAULT_MATCHER_FEE function in PyWaves

    def _postOrder(self, amountAsset, priceAsset, orderType, amount, price, maxLifetime=30*86400, matcherFee=pywaves.DEFAULT_MATCHER_FEE, timestamp=0):
        if timestamp == 0:
            timestamp = int(time.time() * 1000)
        expiration = timestamp + maxLifetime * 1000
        asset1 = b'\0' if amountAsset.assetId=='' else b'\1' + base58.b58decode(amountAsset.assetId)
        asset2 = b'\0' if priceAsset.assetId=='' else b'\1' + base58.b58decode(priceAsset.assetId)
        sData = base58.b58decode(self.publicKey) + \
                base58.b58decode(pywaves.MATCHER_PUBLICKEY) + \
                asset1 + \
                asset2 + \
                orderType + \
                struct.pack(">Q", price) + \
                struct.pack(">Q", amount) + \
                struct.pack(">Q", timestamp) + \
                struct.pack(">Q", expiration) + \
                struct.pack(">Q", matcherFee)
        signature = crypto.sign(self.privateKey, sData)