code: def validate(value, format, raise_error=false)
        unless FORMATS.key?(format)
          raise FormatError, "Invalid data format: #{format}"
        end
        result = value =~ FORMATS[format] ? true : false
        if raise_error && !result
          raise ValidationError, "Invalid value \"#{value}\" for #{format}"
        end
        result
      end
docs: Validate data against provided format