fix: enable vendorfield for multipayment (#103)

Author: dated

crypto/transactions/builder/multi_payment.py

@@ -6,10 +6,11 @@ class MultiPayment(BaseTransactionBuilder):
 
     transaction_type = TRANSACTION_MULTI_PAYMENT
 
-    def __init__(self, fee=None):
+    def __init__(self, vendorField=None, fee=None):
         """Create a multi payment transaction
 
         Args:
+            vendorField (str): value for the vendor field aka smartbridge
             fee (int, optional): fee used for the transaction (default is already set)
         """
         super().__init__()
@@ -18,6 +19,8 @@ def __init__(self, fee=None):
 
         self.transaction.asset['payments'] = []
 
+        self.transaction.vendorField = vendorField.encode() if vendorField else None
+
         if fee:
             self.transaction.fee = fee