Bunny.new raises RuntimeError when given frozen array of hosts

[roback]

Bunny raises RuntimeError: can't modify frozen Array when given a frozen array of hosts. The cause of this error is the call to map! in lib/bunny/session.rb. The fact that Bunny is modifying its arguments was (at least to me) unexpected behaviour.

require "bunny"

Bunny::VERSION
# => "2.6.1"

HOSTS = [
  "localhost",
].freeze

Bunny.new(hosts: HOSTS)
# => RuntimeError: can't modify frozen Array
#    from ~/.gem/ruby/2.3.1/gems/bunny-2.6.1/lib/bunny/session.rb:774:in `map!'

Is there is any reason for using map! instead of map here (apart from the minimal performance gain 😄 )?