code: def path_to_pattern(api_path, parameters):
      
      parts = re.split(PARAMETER_REGEX, api_path)
      pattern = ''.join((process_path_part(part, parameters) for part in parts))
  
      if not pattern.startswith('^'):
          pattern = "^{0}".format(pattern)
      if not pattern.endswith('$'):
          pattern = "{0}$".format(pattern)
  
      return pattern
docs: Given an api path, possibly with parameter notation, return a pattern
      suitable for turing into a regular expression which will match request
      paths that conform to the parameter definitions and the api path.