code: def cast(self, val: UOp, dtype) -> UOp:
      return (
          self.uop(UOps.CAST, dtype, (val,))
          if val.dtype != dtype
          else val
      )
  
imports: from __future__ import annotations
  from typing import List, Tuple, Any, Optional, cast, DefaultDict, Dict, Union, Sequence, Final, Set, Iterator
  import itertools, math, functools
  from collections import defaultdict
  from enum import Enum, auto
  from dataclasses import dataclass
  from tinygrad.dtype import ImageDType, dtypes, DType, PtrDType
  from tinygrad.helpers import colored, DEBUG, prod, getenv, all_same, to_function_name, flatten
  from tinygrad.ops import LazyOp, UnaryOps, BinaryOps, TernaryOps, ReduceOps, ConstBuffer, MemBuffer, BufferOps, get_lazyop_info
  from tinygrad.shape.shapetracker import ShapeTracker
  from tinygrad.shape.symbolic import Variable, NumNode, Node, SumNode, MulNode, DivNode, ModNode, LtNode, AndNode
  from tinygrad.codegen.kernel import LocalBuffer, Kernel
  from tinygrad.features.image import to_image_idx
label_desc: Use image node_id 3 for calling the Linearizer obj's underlying member method code with example usage: obj.cast(val, dtype) and returns: unknown