code: def test_assumptions():
      rl = rewriterule(x + y, x**y, [x, y], assume=Q.integer(x))
  
      a, b = map(Symbol, "ab")
      expr = a + b
      assert list(rl(expr, Q.integer(b))) == [b**a]
  
file_path: sympy/sympy/unify/tests/test_rewrite.py
imports: from sympy.unify.rewrite import rewriterule
  from sympy.core.basic import Basic
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol
  from sympy.functions.elementary.trigonometric import sin
  from sympy.abc import x, y
  from sympy.strategies.rl import rebuild
  from sympy.assumptions import Q
label_desc: Use image node_id 8 for calling a global function with example usage: test_assumptions() without return types