code: def test_exp2():
      # Eval
      assert exp2(2) == 4
  
      x = Symbol("x", real=True)
  
      # Expand
      assert exp2(x).expand(func=True) - 2**x == 0
  
      # Diff
      assert exp2(42 * x).diff(x) - 42 * exp2(42 * x) * log(2) == 0
      assert exp2(42 * x).diff(x) - exp2(42 * x).diff(x) == 0
  
file_path: sympy/sympy/codegen/tests/test_cfunctions.py
imports: from sympy.core.numbers import Rational, pi
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol, symbols
  from sympy.functions.elementary.exponential import exp, log
  from sympy.codegen.cfunctions import expm1, log1p, exp2, log2, fma, log10, Sqrt, Cbrt, hypot
  from sympy.core.function import expand_log
label_desc: Use image node_id 3 for calling a global function with example usage: test_exp2() without return types