input: def most_efficient_order(tasks):
      """
      This method takes a list of tasks and produces the most efficient order for completing the tasks.
  
      Parameters
      ----------
      tasks: List
          A list of tasks to be performed.
  
      Returns
      -------
      List
          An ordered list of tasks representing the most efficient order for completing the tasks.
      >>> most_efficient_order([Task1, Task2, Task3, Task4, Task5])
      [Task1, Task3, Task2, Task5, Task4]
      """
output:     from itertools import permutations
  
      def calculate_efficiency(order):
          # Placeholder for a function that calculates the efficiency of a given order
          return sum(task.duration for task in order)
  
      best_order = None
      best_efficiency = float('inf')
  
      for order in permutations(tasks):
          efficiency = calculate_efficiency(order)
          if efficiency < best_efficiency:
              best_efficiency = efficiency
              best_order = order
  
      return list(best_order)