code: def set_attributes(node, overwrite=True, **attributes):
      
      aset = node.attrs
      for k, v in attributes.items():
          if not overwrite and k in aset:
              pass
          elif v is None:
              if k in aset:
                  del aset[k]
          else:
              aset[k] = v
docs: Set multiple attributes on node.
  
      If overwrite is False, and the attribute already exists, does nothing. If
      the value for a key is None, the attribute is deleted.