`chain/1` disappears from iex

[florius0]

If chain/1 is called inside iex session once and I try to call it the second time, Elixir tells that chain/1 does not exist. use Witchcraft or use Witchcraft.Chain fixes it.

Erlang/OTP 24 [erts-12.1.2] [source] [64-bit] [smp:12:12] [ds:12:12:10] [async-threads:1] [jit] [dtrace]

Interactive Elixir (1.12.3) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> use Witchcraft
Witchcraft
iex(2)> chain do
...(2)> [1,2,3]
...(2)> [4,5,6]
...(2)> end
[4, 5, 6, 4, 5, 6, 4, 5, 6]
iex(3)> chain do
...(3)> [1,2,3]
...(3)> [4,5,6]
...(3)> end
** (CompileError) iex:3: undefined function chain/1

iex(3)> use Witchcraft
Witchcraft
iex(4)> chain do
...(4)> [1,2,3]
...(4)> [4,5,6]
...(4)> end
[4, 5, 6, 4, 5, 6, 4, 5, 6]
iex(5)> chain do
...(5)> [1,2,3]
...(5)> [4,5,6]
...(5)> end
** (CompileError) iex:5: undefined function chain/1

iex(5)>