code: def weld_udf(weld_template, mapping):
      
      weld_obj = create_empty_weld_object()
  
      for k, v in mapping.items():
          if isinstance(v, (np.ndarray, WeldObject)):
              obj_id = get_weld_obj_id(weld_obj, v)
              mapping.update({k: obj_id})
  
      weld_obj.weld_code = weld_template.format(**mapping)
  
      return weld_obj
docs: Create WeldObject to encode weld_template code given mapping.
  
      Parameters
      ----------
      weld_template : str
          Weld code to encode.
      mapping : dict
          Which substitutions to make in the weld_template.
  
      Returns
      -------
      WeldObject
          Representation of this computation.