code: def opaque_block(a: T.handle) -> None:
      A = T.match_buffer(a, (16,))
      for i in T.serial(0, 15):
          with T.block("opaque"):
              A[i + 1] = A[i + 1] + A[i]
  
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 16 for calling a global function with example usage: opaque_block(a) without return types