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: rubygems.rb
    path of file: ./repos/artichoke/artichoke-backend/vendor/ruby/lib
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
#--
# Cop
    
  def self.paths=(env)
    clear_paths
    target = {}
    env.each_pair do |k,v|
      case k
      when 'GEM_HOME', 'GEM_PATH', 'GEM_SPEC_CACHE'
        case v
        when nil, String
          target[k] = v
        when Array
          unless Gem::Deprecate.skip
            warn <<-EOWARN
Array values in the parameter to `Gem.paths=` are deprecated.
Please use a String or nil.
An Array (#{env.inspect}) was passed in from #{caller[3]}
            EOWARN
          end
          target[k] = v.join File::PATH_SEPARATOR
        end