prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Broken multiple interface notation in schema
  ### What I'm trying to achieve
  To use Apollo tooling to generate TS types for the application queries. However, it fails because Saleor's schema uses comma as a separator instead of ampersand. More: https://github.com/apollographql/apollo-tooling/issues/434 
  
  ### Steps to reproduce the problem
  1. Go to mirumee/saleor-dashboard repository and clone it
  2. Copy schema from core to dashboard
  3. `npm run build-types`
  4. Notice that it fails at multiple interface implementation.
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `saleor/graphql/management/commands/get_graphql_schema.py`
  Content:
  ```
  1 from django.core.management.base import BaseCommand
  2 from graphql import print_schema
  3 
  4 from ...api import schema
  5 
  6 
  7 class Command(BaseCommand):
  8     help = "Writes SDL for GraphQL API schema to stdout"
  9 
  10     def handle(self, *args, **options):
  11         self.stdout.write(print_schema(schema))
  12
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/saleor/graphql/management/commands/get_graphql_schema.py b/saleor/graphql/management/commands/get_graphql_schema.py
  --- a/saleor/graphql/management/commands/get_graphql_schema.py
  +++ b/saleor/graphql/management/commands/get_graphql_schema.py
  @@ -8,4 +8,14 @@
       help = "Writes SDL for GraphQL API schema to stdout"
   
       def handle(self, *args, **options):
  -        self.stdout.write(print_schema(schema))
  +        """Support multiple interface notation in schema for Apollo tooling.
  +
  +        In `graphql-core` V2 separator for interaces is `,`.
  +        Apollo tooling to generate TypeScript types using `&` as interfaces separator.
  +        https://github.com/graphql-python/graphql-core/pull/258
  +        """
  +        printed_schema = print_schema(schema)
  +        for line in printed_schema.splitlines():
  +            if "implements" in line:
  +                line = line.replace(",", " &")
  +            self.stdout.write(f"{line}\n")
  
verification_info: {"golden_diff": "diff --git a/saleor/graphql/management/commands/get_graphql_schema.py b/saleor/graphql/management/commands/get_graphql_schema.py\n--- a/saleor/graphql/management/commands/get_graphql_schema.py\n+++ b/saleor/graphql/management/commands/get_graphql_schema.py\n@@ -8,4 +8,14 @@\n     help = \"Writes SDL for GraphQL API schema to stdout\"\n \n     def handle(self, *args, **options):\n-        self.stdout.write(print_schema(schema))\n+        \"\"\"Support multiple interface notation in schema for Apollo tooling.\n+\n+        In `graphql-core` V2 separator for interaces is `,`.\n+        Apollo tooling to generate TypeScript types using `&` as interfaces separator.\n+        https://github.com/graphql-python/graphql-core/pull/258\n+        \"\"\"\n+        printed_schema = print_schema(schema)\n+        for line in printed_schema.splitlines():\n+            if \"implements\" in line:\n+                line = line.replace(\",\", \" &\")\n+            self.stdout.write(f\"{line}\\n\")\n", "issue": "Broken multiple interface notation in schema\n### What I'm trying to achieve\r\nTo use Apollo tooling to generate TS types for the application queries. However, it fails because Saleor's schema uses comma as a separator instead of ampersand. More: https://github.com/apollographql/apollo-tooling/issues/434 \r\n\r\n### Steps to reproduce the problem\r\n1. Go to mirumee/saleor-dashboard repository and clone it\r\n2. Copy schema from core to dashboard\r\n3. `npm run build-types`\r\n4. Notice that it fails at multiple interface implementation.\n", "before_files": [{"content": "from django.core.management.base import BaseCommand\nfrom graphql import print_schema\n\nfrom ...api import schema\n\n\nclass Command(BaseCommand):\n    help = \"Writes SDL for GraphQL API schema to stdout\"\n\n    def handle(self, *args, **options):\n        self.stdout.write(print_schema(schema))\n", "path": "saleor/graphql/management/commands/get_graphql_schema.py"}], "after_files": [{"content": "from django.core.management.base import BaseCommand\nfrom graphql import print_schema\n\nfrom ...api import schema\n\n\nclass Command(BaseCommand):\n    help = \"Writes SDL for GraphQL API schema to stdout\"\n\n    def handle(self, *args, **options):\n        \"\"\"Support multiple interface notation in schema for Apollo tooling.\n\n        In `graphql-core` V2 separator for interaces is `,`.\n        Apollo tooling to generate TypeScript types using `&` as interfaces separator.\n        https://github.com/graphql-python/graphql-core/pull/258\n        \"\"\"\n        printed_schema = print_schema(schema)\n        for line in printed_schema.splitlines():\n            if \"implements\" in line:\n                line = line.replace(\",\", \" &\")\n            self.stdout.write(f\"{line}\\n\")\n", "path": "saleor/graphql/management/commands/get_graphql_schema.py"}]}