bugfix: fix import module

djangoldp_invoice/models.py

@@ -73,7 +73,7 @@ class CustomerInvoice(Model):
     class Meta:
         depth = 2
         container_path = "customer-invoices/"
-        nested_fields = ["batches", "project", "customer"],
+        nested_fields = ["batches", "project", "customer"]
         serializer_fields = ["@id", "identifier", "title", "state", "htAmount", "tvaRate", "invoicingDate",
                              "tvaAmount", "ttcAmount", "batches", "project", "customer"]
         permissions = (
@@ -93,7 +93,7 @@ class Batch(Model):
     modificationDate = models.DateField(auto_now=True)
 
     class Meta:
-        nested_fields=["tasks"],
+        nested_fields = ["tasks"]
         serializer_fields = ['@id', 'invoice', 'title', 'htAmount', 'tasks']
         permissions = (
             ('view_batch', 'Read'),