<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def discover(self, exclude=None):
 """Automatically discovers and registers installed formats. If a format is already registered with an exact same name, the discovered format will not be registered. :param exclude: (optional) Exclude formats from registering """

        if exclude is None:
            exclude = []
        elif not isinstance(exclude, (list, tuple)):
            exclude = [exclude]

        if 'json' not in exclude and 'json' not in self.registered_formats:
            self.discover_json()
        if 'yaml' not in exclude and 'yaml' not in self.registered_formats:
            self.discover_yaml()