    def to_yaml(self, data, options=None):
        """
        Given some Python data, produces YAML output.
        """
        options = options or {}
        
        if yaml is None:
            raise ImproperlyConfigured("Usage of the YAML aspects requires yaml.")
        
        return yaml.dump(self.to_simple(data, options))
The product receives input or data, but it does
        not validate or incorrectly validates that the input has the
        properties that are required to process the data safely and
        correctly.