code: def forward(self, a: LazyBuffer, b: LazyBuffer) -> LazyBuffer:
      assert (
          prod(a.shape) == prod(b.shape) and a.device == b.device
      ), "shape or device mismatch"
      self.a, self.b = a, b
      return create_lazybuffer(
          a.device,
          ShapeTracker.from_shape(a.shape),
          max(a.dtype, b.dtype),
          LoadOps.CUSTOM,
          arg={"GPU": atan2_gpu, "CPU": atan2_cpu}[a.device],
          srcs=(a.contiguous(), b.contiguous()),
      )
  
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 1 for calling the ATan2 obj's underlying member method code with example usage: obj.forward(a, b) and returns: create_lazybuffer