old_contents: from robber import expect
  from base import Base
  
  class Above(Base):
      def matches(self):
          return self.actual > self.expected
  
      def failure_message(self):
          return 'Expected %d to be above %d' % (self.actual, self.expected)
  
  class Below(Base):
      def matches(self):
          return self.actual < self.expected
  
      def failure_message(self):
          return 'Expected %d to be below %d' % (self.actual, self.expected)
  
  class Within(Base):
      def matches(self):
          return self.expected <= self.actual <= self.args[0]
  
      def failure_message(self):
          return 'Expected %d to be within %d and %d' % (self.actual, self.expected, self.args[0])
  
  expect.register('above', Above)
  expect.register('below', Below)
  expect.register('within', Within)
  
new_contents: from robber import expect
  from base import Base
  
  class Above(Base):
      """
      expect(2).to.be.above(1)
      """
      def matches(self):
          return self.actual > self.expected
  
      def failure_message(self):
          return 'Expected %d to be above %d' % (self.actual, self.expected)
  
  class Below(Base):
      """
      expect(1).to.be.below(2)
      """
      def matches(self):
          return self.actual < self.expected
  
      def failure_message(self):
          return 'Expected %d to be below %d' % (self.actual, self.expected)
  
  class Within(Base):
      """
      expect(1).to.be.within(0, 2)
      """
      def matches(self):
          return self.expected <= self.actual <= self.args[0]
  
      def failure_message(self):
          return 'Expected %d to be within %d and %d' % (self.actual, self.expected, self.args[0])
  
  expect.register('above', Above)
  expect.register('below', Below)
  expect.register('within', Within)
  
subject: Add docs for numbers