input: Write a function that prints out the largest value from a given list of numbers. If the list is empty, print "No numbers in the list". Perform the operation by iterating through the list.
  
  assert get_max_value([2, 4, 1, 6])==6
  assert get_max_value([])=='No numbers in the list'
output: def get_max_value(numbers):
      if not numbers:
          return "No numbers in the list"
      max_value = numbers[0]
      for num in numbers:
          if num > max_value:
              max_value = num
      return max_value