input: Write a python function to compare two instances of the Comparable class.
  assert compare_comparable(Comparable(10), Comparable(5)) == 1
  assert compare_comparable(Comparable(5), Comparable(10)) == -1
  assert compare_comparable(Comparable(7), Comparable(7)) == 0
output: class Comparable:
      def __init__(self, value):
          self.value = value
  
  def compare_comparable(a: Comparable, b: Comparable) -> int:
      if a.value > b.value:
          return 1
      elif a.value < b.value:
          return -1
      else:
          return 0