code: def test_awaitable_property_slicing(self, test_env_async):
      t = test_env_async.from_string(
          "{% for x in a.b[:1] %}{{ x }}{% endfor %}"
      )
      assert t.render(a=dict(b=[1, 2, 3])) == "1"
  
imports: import asyncio
  import pytest
  from jinja2 import DictLoader
  from jinja2 import Environment
  from jinja2 import Template
  from jinja2.asyncsupport import auto_aiter
  from jinja2.exceptions import TemplateNotFound
  from jinja2.exceptions import TemplatesNotFound
  from jinja2.exceptions import UndefinedError
label_desc: Use image node_id 28 for calling the TestAsyncForLoop obj's underlying member method code with example usage: obj.test_awaitable_property_slicing(test_env_async) without return types