def get_longest_consecutive_chars(string):
    """
    Given a string, return the longest consecutive character sequence.
    """
    longest_consecutive_chars = ''
    current_consecutive_chars = ''

    for char in string:
        if char not in current_consecutive_chars:
            current_consecutive_chars += char
        else:
            current_consecutive_chars = char

        if len(current_consecutive_chars) > len(longest_consecutive_chars):
            longest_consecutive_chars = current_consecutive_chars

    return longest_consecutive_chars