code: def get(self, pattern):
          '''
          Get a compiled regular expression object based on pattern and
          cache it when it is not in the cache already
          '''
          try:
              self.cache[pattern][0] += 1
              return self.cache[pattern][1]
          except KeyError:
              pass
          if len(self.cache) > self.size:
              self.sweep()
          regex = re.compile('{0}{1}{2}'.format(
              self.prepend, pattern, self.append))
          self.cache[pattern] = [1, regex, pattern, time.time()]
          return regef get(self, pattern):
          '''
          Get a compiled regular expression object based on pattern and
          cache it when it is not in the cache already
          '''
          try:
              self.cache[pattern][0] += 1
              return self.cache[pattern][1]
          except KeyError:
              pass
          if len(self.cache) > self.size:
              self.sweep()
          regex = re.compile('{0}{1}{2}'.format(
              self.prepend, pattern, self.append))
          self.cache[pattern] = [1, regex, pattern, time.time()]
          return regex
docs: Get a compiled regular expression object based on pattern and
          cache it when it is not in the cache already