You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: boolean.rb
    path of file: ./repos/gitlabhq/lib/gitlab/redis
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

# A serializer for boolean values being stored in Redis.
#
# This is to ensure that booleans are stored in a consistent and
# testable way 
    
        def decode(value)
          raise NotAnEncodedBooleanStringError, value.class unless value.is_a?(String)

          label, bool_str = *value.split(DELIMITER, 2)

          raise NotAnEncodedBooleanStringError, label unless label == LABEL

          from_string(bool_str)
        end