code: def test_dispatcher():
      f = Dispatcher("f")
      f.add((int,), inc)
      f.add((float,), dec)
  
      with warns(DeprecationWarning, test_stacklevel=False):
          assert f.resolve((int,)) == inc
      assert f.dispatch(int) is inc
  
      assert f(1) == 2
      assert f(1.0) == 0.0
  
imports: from sympy.multipledispatch.dispatcher import Dispatcher, MDNotImplementedError, MethodDispatcher, halt_ordering, restart_ordering, ambiguity_register_error_ignore_dup
  from sympy.testing.pytest import raises, warns
label_desc: Use image node_id 4 for calling a global function with example usage: test_dispatcher() without return types