auto m = ["k":"v"]

// find existing key returns the value
assert_equal("v", m.find("k"))

// find missing key returns undef
assert_true(m.find("missing").is_var_undef())

// find does not mutate the map
m.find("other")
assert_equal(1, m.size())

// find works with in-place map
assert_equal("v", ["k":"v"].find("k"))