code: def forward(
      self,
      x_proj: LazyTensor,
      y_proj: LazyTensor,
      x: Optional[LazyTensor] = None,
      y: Optional[LazyTensor] = None,
  ) -> LazyTensor:
      similarity = self.kernel_a(x_proj, y_proj)
      if self.kernel_b is not None:
          similarity = (
              1 - self.eps
          ) * similarity + self.eps * self.kernel_b(x, y)
      return similarity
  
imports: from pykeops.torch import LazyTensor
  import torch
  import torch.nn
  from typing import Callable, Optional, Union
  from alibi_detect.utils.frameworks import Framework
  from alibi_detect.utils._types import Literal
  from copy import deepcopy
label_desc: Use image node_id 4 for calling the DeepKernel obj's underlying member method code with example usage: obj.forward(x_proj, y_proj, x, y) and returns: similarity