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: functions.rb
    path of file: ./repos/puppet/lib/puppet/parser
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require_relative '..
    
  def self.newfunction(name, options = {}, &block)
    name = name.intern
    environment = options[:environment] || Puppet.lookup(:current_environment)

    Puppet.warning _("Overwriting previous definition for function %{name}") % { name: name } if get_function(name, environment)

    arity = options[:arity] || -1
    ftype = options[:type] || :statement

    unless ftype == :statement or ftype == :rvalue
      raise Puppet::DevError, _("Invalid statement type %{type}") % { type: ftype.inspect }
    end