Validates the data received as keyword arguments whose name match
        this class attributes.

def validate(cls, **kwargs):
        ''' Validates the data received as keyword arguments whose name match
        this class attributes. '''
        # errors can store multiple errors
        # obj is an instance in case validation succeeds
        # redis is needed for database validation
        errors = ValidationErrors()
        obj = cls()
        redis = cls.get_redis()

        # Check the fields
        for fieldname, field in obj.proxy:
            if not field.fillable:
                value = field.default
            else:
                try:
                    value = field.validate(kwargs.get(fieldname), redis)
                except BadField as e:
                    errors.append(e)
                    continue

            setattr(
                obj,
                fieldname,
                value
            )

        # Check for custom validation rules
        for fieldname in dir(cls):
            rule = getattr(cls, fieldname)

            if hasattr(rule, '_is_validation_rule') and rule._is_validation_rule:
                try:
                    rule(obj)
                except BadField as e:
                    errors.append(e)

        # Trigger errors if any
        if errors.has_errors():
            raise errors

        # Return the object with the new data set
        return obj