code: def test_symbols_are_created_once():
      """
      Test that a symbol is cached and reused when it appears in an expression
      more than once.
      """
      expr = sy.Add(x, x, evaluate=False)
      comp = aesara_code_(expr)
  
      assert theq(comp, xt + xt)
      assert not theq(comp, xt + aesara_code_(x))
  
imports: import logging
  from sympy.external import import_module
  from sympy.testing.pytest import raises, SKIP
  from sympy.utilities.exceptions import ignore_warnings
  import sympy
  from sympy.core.singleton import S
  from sympy.abc import x, y, z, t
  from sympy.printing.aesaracode import aesara_code, dim_handling, aesara_function
label_desc: Use image node_id 40 for calling a global function with example usage: test_symbols_are_created_once() without return types