code: def topk(expr, type_map):
      """Rewrite a topk op"""
      arg = expr.args[0]
      t = type_map[arg]
      attrs = {**expr.attrs}
      assert "ret_type" in attrs and attrs["ret_type"] == "values"
      return [expr, t]
  
imports: import numpy
  import tvm
  from tvm import relay
  from tvm.ir import TensorAffineType, TupleAffineType
  from tvm.relay.qnn.op import canonicalizations
  from tvm.tir import bijective_layout
  from ..op import register_fake_quantization_to_integer, register_optional_fake_quantization_to_integer
label_desc: Use image node_id 18 for calling a global function with example usage: topk(expr, type_map) and returns: list