old_contents: 
  class Result:
  
      def __init__(self, return_code, stdout, stderr):
          self.return_code = return_code
          self.stdout = stdout
          self.stderr = stderr
          self.succeeded = self.return_code == 0
          self.failed = not self.succeeded
          self.stdout_lines = stdout.splitlines() if stdout else []
          self.stderr_lines = stderr.splitlines() if stderr else []
  
new_contents: from ..util import cached_property
  
  
  class Result:
  
      def __init__(self, return_code, stdout, stderr):
          self.return_code = return_code
          self.stdout = stdout
          self.stderr = stderr
          self.succeeded = self.return_code == 0
          self.failed = not self.succeeded
  
      @cached_property
      def stdout_lines(self):
          return self.stdout.splitlines() if self.stdout else []
  
      @cached_property
      def stderr_lines(self):
          return self.stderr.splitlines() if self.stderr else []
  
subject: Make Result.stdout_lines and stderr_lines cached properties