one step closer to the behavior we want.

$ rake pry
[1] pry(main)> _pry_.config.requires
=> []
[2] pry(main)> _pry_.config.requires << 1
=> [1]
[3] pry(main)> Pry.config.requires = [1,2,3]
=> [1, 2, 3]
[4] pry(main)> _pry_.config.requires
=> [1, 2, 3]
[5] pry(main)> _pry_.config.requires = [42]
=> [42]
[6] pry(main)> Pry.config.requires = [5667]
=> [5667]
[7] pry(main)> _pry_.config.requires
=> [42]
[8] pry(main)> exit