code: def lhs(node):
      '''
      Return a set of symbols in `node` that are assigned.
      
      :param node: ast node 
      
      :returns: set of strings.
      '''
  
      gen = ConditionalSymbolVisitor()
      if isinstance(node, (list, tuple)):
          gen.visit_list(node)
      else:
          gen.visit(node)
      return gen.lhf lhs(node):
      '''
      Return a set of symbols in `node` that are assigned.
      
      :param node: ast node 
      
      :returns: set of strings.
      '''
  
      gen = ConditionalSymbolVisitor()
      if isinstance(node, (list, tuple)):
          gen.visit_list(node)
      else:
          gen.visit(node)
      return gen.lhs
docs: Return a set of symbols in `node` that are assigned.
      
      :param node: ast node 
      
      :returns: set of strings.