class Opal::Nodes::Args::ExtractKwrestarg


and as a local variable when it’s not)
$kwargs always exist (as argument when inlining is possible
splat keyword argument from $kwargs
This node is responsible for extracting a single

def compile 

def compile
  # def m(**)
  # arguments are assigned to `$kw_rest_arg` for super call
  name = self.name || '$kw_rest_arg'
  add_temp name
  line "#{name} = Opal.kwrestargs($kwargs, #{used_kwargs});"
end

def used_kwargs 

def used_kwargs
  args = scope.used_kwargs.map do |arg_name|
    "'#{arg_name}': true"
  end
  "{#{args.join ','}}"
end