def decode(string)
      padding_size  = string.bytesize % 4
      padded_string = padding_size > 0 ? string + '=' * (4 - padding_size) : string

      Base64.urlsafe_decode64(padded_string)
    end
def decode(string)
      padding_size  = string.bytesize % 4
      padded_string = padding_size > 0 ? string + '=' * (4 - padding_size) : string

      Base64.urlsafe_decode64(padded_string)
    end
Decode an unpadded URL-safe Base64 string

 @param string [String] URL-safe Base64 string to be decoded (sans '=' padding)
 @return [String] decoded string