old_contents: from lib import action
  
  
  class VaultReadAction(action.VaultBaseAction):
      def run(self, path):
          return self.vault.read(path)['data']
  
new_contents: from lib import action
  
  
  class VaultReadAction(action.VaultBaseAction):
      def run(self, path):
          value = self.vault.read(path)
          if value:
              return value['data']
          else:
              raise KeyError("Key was not found in Vault")
  
subject: Make `vault.read` raise meaningful exception