code: def test_exp():
      e = exp(x).lseries(x)
      assert next(e) == 1
      assert next(e) == x
      assert next(e) == x**2 / 2
      assert next(e) == x**3 / 6
  
file_path: sympy/sympy/series/tests/test_lseries.py
imports: from sympy.core.numbers import E
  from sympy.core.singleton import S
  from sympy.functions.elementary.exponential import exp
  from sympy.functions.elementary.hyperbolic import tanh
  from sympy.functions.elementary.trigonometric import cos, sin
  from sympy.series.order import Order
  from sympy.abc import x, y
label_desc: Use image node_id 3 for calling a global function with example usage: test_exp() without return types