curb.rb

module Curl
  
  class Easy
    def self.performe
      puts "TEST method"
    end
    puts "easy"
    attr_accessor :body_str, :header_str, :response_code
  end
end

gistfile2.rb

irb(main):001:0> require 'fake_web/ext/curb'
=> true
irb(main):002:0> Curl::Easy.performe
NameError: uninitialized constant Curl
	from (irb):2

irb(main):001:0> require 'fake_web/ext/curb'
easy
=> true