class Hash

We don’t necessarily have ActiveSupport loaded yet!

def symbolize_keys

Return a new hash with all keys converted to symbols. 
def symbolize_keys
  inject({}) do |options, (key, value)|
    options[key.to_sym || key] = value
    options
  end
end

def symbolize_keys!

Destructively convert all keys to symbols. 
def symbolize_keys!
  self.replace(self.symbolize_keys)
end