You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: funcall.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/sass-3.4.24/lib/sass/script/tree
    
    the code of the file until where you have to start completion: require 'sass/script/functions'
require 'sass/util'

module Sass::Script::Tree
  # A SassScript parse node representing a function call.
  #
  # A function call either calls one of the functions in
  # {Sass::Script::Functions}, or if no function with the given name exists it
  # returns a string representation of t
    
    def to_sass(opts = {})
      arg_to_sass = lambda do |arg|
        sass = arg.to_sass(opts)
        sass = "(#{sass})" if arg.is_a?(Sass::Script::Tree::ListLiteral) && arg.separator == :comma
        sass
      end

      args = @args.map(&arg_to_sass)
      keywords = Sass::Util.hash_to_a(@keywords.as_stored).
        map {|k, v| "$#{dasherize(k, opts)}: #{arg_to_sass[v]}"}

      # rubocop:disable RedundantSelf
      if self.splat
        splat = "#{arg_to_sass[self.splat]}..."
        kwarg_splat = "#{arg_to_sass[self.kwarg_splat]}..." if self.kwarg_splat
      end