input: from typing import List
  
  def finds_index_of_minimum(numbers: List[int]) -> int:
      """
      Given a list of integers, find the index of the minimum value in the list.
      If the list is empty, return -1. If there are multiple minimum values, return the index of the first occurrence.
      
      >>> finds_index_of_minimum([3, 1, 4, 1, 5, 9, 2, 6])
      1
      >>> finds_index_of_minimum([-5, 10, -5, -10, -20])
      4
      >>> finds_index_of_minimum([])
      -1
      """
output:     if not numbers:
          return -1
      
      min_index = 0
      for i in range(1, len(numbers)):
          if numbers[i] < numbers[min_index]:
              min_index = i
      
      return min_index