new_contents: 
  from nodes import Node
  
  class MultiVar(Node):
      char = "'"
      args = 0
      results = None
      contents = -1
      
      def __init__(self, node_1: Node.NodeSingle, node_2: Node.NodeSingle):
          self.node_1 = node_1
          self.node_2 = node_2
          self.args = max([node_1.args, node_2.args])
          
      def prepare(self, stack):
          if len(stack) == 0:
              self.add_arg(stack)
  
      @Node.is_func
      def apply(self, *stack):
          self.node_2.prepare(stack)
          rtn = self.node_2(stack)
          self.node_1.prepare(stack)
          rtn.extend(self.node_1(stack))
          return rtn
  
subject: Add multi_var