def copy_labels(src, dst):
    """
    Copies all labels of one object to another object.

    :type  src: object
    :param src: The object to check read the labels from.
    :type  dst: object
    :param dst: The object into which the labels are copied.
    """
    labels = src.__dict__.get('_labels')
    if labels is None:
        return
    dst.__dict__['_labels'] = labels.copy()
