class Psych::ClassLoader::Restricted

def find klassname
  if @classes.include? klassname
    super
  else
    raise DisallowedClass, klassname
  end
end

def initialize classes, symbols
  @classes = classes
  @symbols = symbols
  super()
end

def symbolize sym
  return super if @symbols.empty?
  if @symbols.include? sym
    super
  else
    raise DisallowedClass, 'Symbol'
  end
end