class Opal::Nodes::Args::ExtractKwoptarg


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

def compile 

def compile
  key_name = @sexp.meta[:arg_name]
  scope.used_kwargs << key_name
  add_temp lvar_name
  line "#{lvar_name} = $kwargs.$$smap[#{key_name.to_s.inspect}];"
  return if default_value.children[1] == :undefined
  line "if (#{lvar_name} == null) #{lvar_name} = ", expr(default_value)
end