human
Solve the following python programming problem given the following code:
def ensure_group(self, group_name, group_id = None) : 
    "
        Ensures that a given user group is present in the remote server.

        :param group_name: Name of the group to create.
        :type group_name: :class:`str`
        :param group_id: GID of the group. Defaults to :data:`None`, which assigns the next available GID.
        :type group_id: :class:`int`

        Example:
        ::

            from provy.core import Role
            from provy.more.debian import UserRole

            class MySampleRole(Role):
                def provision(self):
                    with self.using(UserRole) as role:
                        role.ensure_group('users-group')
        " 
    if (not self.group_exists (group_name)) : 
        self.log (('Group %s not found! Creating...' % group_name)) 
        if (not group_id) : 
            self.execute (('groupadd %s' % group_name), stdout = False, sudo = True) 
else : 
            self.execute (('groupadd --gid %s %s' % (group_id, group_name)), stdout = False, sudo = True) 
self.log (('Group %s created!' % group_id)) 

    
    

    Fix the buggy line: self.log (('Group %s created!' % group_id))
assistant
#Here is Python code to fix the buggy line: self.

self.log (('Group %s created!' % group_name))