gistfile1.txt

[1] pry(main)> class BasicObject
             |   define_method(:instance_variables, ::Kernel.instance_method(:instance_variables))  
             | end  
=> #<UnboundMethod: Kernel#instance_variables>
[2] pry(main)> o = BasicObject.new
=> #<BasicObject:0x3fe8d94cb40c>
[3] pry(main)> o.instance_eval { @x = 10 }
=> 10
[4] pry(main)> o.instance_variables
=> [:@x]
[5] pry(main)> gist -i 1..4