code: def doctest_builtin_underscore():
      """Defining builtins._ should not break anything outside the doctest
      while also should be working as expected inside the doctest.
  
      In [1]: import builtins
  
      In [2]: builtins._ = 42
  
      In [3]: builtins._
      Out[3]: 42
  
      In [4]: _
      Out[4]: 42
      """
  
label_desc: Use image node_id 5 for calling a global function with example usage: doctest_builtin_underscore() without return types