@staticmethod
def _remove_duplicate_formats(formats):
    format_urls = set()
    unique_formats = []
    for f in formats:
        if (f['url'] not in format_urls):
            format_urls.add(f['url'])
            unique_formats.append(f)
    formats[:] = unique_formats
@staticmethod
def _remove_duplicate_formats(formats):
    format_urls = set()
    unique_formats = []
    for f in formats:
        if (f['url'] not in format_urls):
            format_urls.add(f['url'])
            unique_formats.append(f)
    formats[:] = unique_formats