code: def test_parallel_reduction_block_iter():
      s = tir.Schedule(matmul, debug_mask="all")
      _, _, k = s.get_loops(s.get_block("C"))
      with pytest.raises(tvm.tir.ScheduleError):
          s.parallel(k)
  
imports: import sys
  import pytest
  import tvm
  import tvm.testing
  from tvm import tir
  from tvm.script import tir
  from tvm.tir.schedule.testing import verify_trace_roundtrip, assert_structural_equal_ignore_global_symbol
label_desc: Use image node_id 30 for calling a global function with example usage: test_parallel_reduction_block_iter() without return types