old_contents: class Coordinate(object):
      def __init__(self, x=0, y=0):
          self = x
  
new_contents: import math
  
  class Coordinate(object):
      def __init__(self, x=0, y=0):
          self.x = x
          self.y = y
          
      def __str__(self):
          return "<" + str(self.x) + "," + str(self.y) + ">"
          
      def distance(self, other):
          return math.sqrt(pow((self.x - other.x), 2) + pow((self.y - other.y), 2))
subject: add __str__ and distance methods