def _find_similar(other_cl, population):
    """
    Searches for the first similar classifier `other` and returns it.
    Similarity is distinguished when both C-A-E triple is the same.

    Parameters
    ----------
    other_cl:
        classifier to compare

    Returns
    -------
    Optional[Classifier]
        classifier (with the same condition, action, effect),
        None otherwise
    """
    return next(filter(lambda cl: cl == other_cl, population), None)
