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: finalizer__2.rb
    path of file: ./repos/sorbet/test/testdata/compiler/regression
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
# typed: strict
# compiled: true

module Opus; end
module Opus::Utils
  module DeepFreeze
    extend T::Sig

    # Freeze a given object, and return all sub-items that also need freezing
    sig {params(todo: T::Array[T.untyped], obj: T.untyped).void.
    
    def self.freeze_unchecked!(obj)
      todo = [T.unsafe(obj)]
      seen = {}

      until todo.empty?
        o = todo.pop

        case o
        when NilClass, TrueClass, FalseClass
          # don't need to be frozen
          nil
        # Short circuit on common classes.
        # Dispatch on one class, so that the compiler has separate inline caches per function call
        when Symbol
          o.freeze
        when Numeric
          o.freeze
        when String
          o.freeze
        else
          # Skip if we've already seen this object
          if !seen[o.object_id]
            seen[o.object_id] = true
            freeze_one(todo, o)
          end
        end