code: def test_assignment_expression(self):
      code = """
              x = -1
              items = [(x:=y) for y in range(3)]
          """
      outputs = {"x": 2}
      # assignment expression in comprehension is disallowed in class scope
      self._check_in_scopes(
          code, outputs, scopes=["module", "function"]
      )
  
imports: import doctest
  import textwrap
  import types
  import unittest
label_desc: Use image node_id 15 for calling the ListComprehensionTest obj's underlying member method code with example usage: obj.test_assignment_expression() without return types