class RSpec::Core::MemoizedHelpers::BeforeAllMemoizedHash

def self.isolate_for_before_all(example_group_instance)
  example_group_instance.instance_eval do
    @__memoized = BeforeAllMemoizedHash.new(self)
    begin
      yield
    ensure
      @__memoized.preserve_accessed_lets
      @__memoized = nil
    end
  end
end

def []=(key, value)
  @hash[key] = value
end

def fetch(key, &block)
  description = if key == :subject
    "subject"
  else
    "let declaration `#{key}`"
  end
  ::RSpec.warn_deprecation <<-EOS
 #{description} accessed in a `before(:all)` hook at:
er[1]}
deprecated behavior that will not be supported in RSpec 3.
d `subject` declarations are not intended to be called
fore(:all)` hook, as they exist to define state that
 between each example, while `before(:all)` exists to
tate that is shared across examples in an example group.
  @hash.fetch(key, &block)
end

def initialize(example_group_instance)
  @example_group_instance = example_group_instance
  @hash = {}
end

def preserve_accessed_lets
  hash = @hash
  @example_group_instance.class.class_eval do
    hash.each do |key, value|
      undef_method(key) if method_defined?(key)
      define_method(key) { value }
    end
  end
end