'Converts the provided value given a conversion type.
This method decodes the converted value using the formatter\'s coding.
See string.Formatter.convert_field.'

def convert_field(self, value, conversion):

    converted = super(CodingFormatter, self).convert_field(value, conversion)
    try:
        converted = converted.decode(self._coding)
    except UnicodeEncodeError:
        pass
    return converted
