autoflake.py
def filter_duplicate_key(line, message, line_number, marked_line_numbers,
                         source, previous_line=''):
    """Return '' if first occurrence of the key otherwise return `line`."""
    if marked_line_numbers and line_number == sorted(marked_line_numbers)[0]:
        return ''

    return line
def filter_duplicate_key(line, message, line_number, marked_line_numbers,
                         source, previous_line=''):
    """Return '' if first occurrence of the key otherwise return `line`."""
    if marked_line_numbers and line_number == sorted(marked_line_numbers)[0]:
        return ''

    return line
Return '' if first occurrence of the key otherwise return `line`.