new_contents: import pytest
  
  from thinglang.execution.errors import UnknownVariable
  from thinglang.runner import run
  
  
  def test_stack_resolution_in_block():
      assert run("""
  thing Program
      does start
  
          number i = 0
          Output.write("outside before, i =", i)
          if true
              Output.write("inside before, i =", i)
              i = 10
              Output.write("inside after, i =", i)
  
          Output.write("outside after, i =", i)
  
      """).output == """
  outside before, i = 0
  inside before, i = 0
  inside after, i = 10
  outside after, i = 10""".strip()
  
  
  
subject: Add test for general scoping case in nested blocks