code: def _register_sddmm_func():
      """Register sddmm functions"""
      target = ["u", "v", "e"]
      for lhs, rhs in product(target, target):
          if lhs != rhs:
              for binary_op in ["add", "sub", "mul", "div", "dot"]:
                  func = _gen_sddmm_func(lhs, rhs, binary_op)
                  setattr(sys.modules[__name__], func.__name__, func)
                  __all__.append(func.__name__)
  
file_path: dgl/python/dgl/ops/sddmm.py
imports: import sys
  from itertools import product
  from ..None import backend
  from ..backend import gsddmm, gsddmm_hetero
label_desc: Use image node_id 4 for calling a global function with example usage: _register_sddmm_func() without return types