def get(key)
      raise BlankKeyError if key.blank?
      @backend.transaction{
        timestamp!(:last_accessed)
        value = @backend[:user][encrypt(key)]
        raise KeyNotFoundError.new(key) unless value
        EntryMapper.from_json(decrypt(value))
      }
    end
def get(key)
      raise BlankKeyError if key.blank?
      @backend.transaction{
        timestamp!(:last_accessed)
        value = @backend[:user][encrypt(key)]
        raise KeyNotFoundError.new(key) unless value
        EntryMapper.from_json(decrypt(value))
      }
    end
Return the value stored under key