class_docstr: Visitor to locate op on an AST.
class_docstr_tok: ["Visitor","to","locate","op","on","an","AST","."]
docstr: Visit the children.
docstr_tok: ["Visit","the","children","."]
code: def visit_call(self, call):
      """Visit the children."""
      # First visit the children.
      args = [self.visit(arg) for arg in call.args]
  
      odtype = _get_tensor_type(call)
      self.counter += 1
      if (call.op, odtype) in self.op2nodes:
          self.op2nodes[(call.op, odtype)].append(self.counter)
      else:
          self.op2nodes[(call.op, odtype)] = [self.counter]
  
      return relay.Call(self.visit(call.op), args, call.attrs)
  
imports: import tvm
  from tvm import relay
  from tvm.relay import op, transform
  from tvm.relay import ExprMutator
label_desc: Use image node_id 2 for calling the ExprLocator obj's underlying member method code with example usage: obj.visit_call(call) and returns: relay