code: def dot(a, b):
      if a.ndim > 2 and b.ndim > 2:
          return torch.tensordot(a, b, dims=([-1], [-2]))
      if not a.ndim or not b.ndim:
          return a * b
      return torch.matmul(a, b)
  
imports: from packaging.version import Version
  import numpy
  from .core import Backend, backend_types, backend_basic_math, backend_array
label_desc: Use image node_id 12 for calling the PyTorchBackend obj's underlying member method code with example usage: obj.dot(a, b) and returns: torch, torch, unknown