code: def test_subs_with_unicode_symbols():
      expr = Symbol("var1")
      replaced = expr.subs("var1", "x")
      assert replaced.name == "x"
  
      replaced = expr.subs("var1", "x")
      assert replaced.name == "x"
  
imports: import collections
  from typing import TypeVar, Generic
  from sympy.assumptions.ask import Q
  from sympy.core.basic import Basic, Atom, as_Basic, _atomic, _aresame
  from sympy.core.containers import Tuple
  from sympy.core.function import Function, Lambda
  from sympy.core.numbers import I, pi, Float
  from sympy.core.singleton import S
  from sympy.core.symbol import symbols, Symbol, Dummy
  from sympy.concrete.summations import Sum
  from sympy.functions.elementary.trigonometric import cos, sin
  from sympy.functions.special.gamma_functions import gamma
  from sympy.integrals.integrals import Integral
  from sympy.functions.elementary.exponential import exp
  from sympy.testing.pytest import raises, warns_deprecated_sympy
label_desc: Use image node_id 8 for calling a global function with example usage: test_subs_with_unicode_symbols() without return types