class Jbuilder

def _format_keys(hash_or_array)
  return hash_or_array unless @deep_format_keys
  if ::Array === hash_or_array
    hash_or_array.map { |value| _format_keys(value) }
  elsif ::Hash === hash_or_array
    ::Hash[hash_or_array.collect { |k, v| [_key(k), _format_keys(v)] }]
  else
    hash_or_array
  end
end