<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def losc_frame_urls(ifo, start_time, end_time):
 """ Get a list of urls to losc frame files Parameters ifo: str The name of the IFO to find the information about. start_time: int The gps time in GPS seconds end_time: int The end time in GPS seconds Returns ------- frame_files: list A dictionary containing information about the files that span the requested times. """

    data = losc_frame_json(ifo, start_time, end_time)['strain']
    return [d['url'] for d in data if d['format'] == 'gwf']