code: def atan2_cpu(ret: Buffer, a: Buffer, b: Buffer):
      ret.copyin(
          np.require(np.arctan2(a._buf, b._buf), requirements="C").data
      )
  
imports: import unittest
  import numpy
  from typing import Optional, Tuple
  from tinygrad.helpers import prod
  from tinygrad.dtype import dtypes
  from tinygrad.lazy import Buffer, create_lazybuffer
  from tinygrad.device import CompiledASTRunner, Device
  from tinygrad.shape.shapetracker import ShapeTracker
  from tinygrad.ops import LoadOps, BinaryOps
  from tinygrad.lazy import LazyBuffer
  from tinygrad.tensor import Function
  from tinygrad.tensor import Tensor
label_desc: Use image node_id 2 for calling a global function with example usage: atan2_cpu(ret, a, b) without return types