<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def container_exists(self, id=None, name=None):
 """ Checks if container exists already """

        exists = False
        if id and self.container_by_id(id):
            exists = True
        elif name and self.container_by_name(name):
            exists = True

        return exists