Return a tuple of (years, months) from a dict of date elements.

    Accepts a dict containing any of the following:
      - years
      - months

    Example:

    >>> _year_month_delta_from_elements({'years': 2, 'months': 14})
    (3, 2)

def _year_month_delta_from_elements(elements):
    """
    Return a tuple of (years, months) from a dict of date elements.

    Accepts a dict containing any of the following:
      - years
      - months

    Example:

    >>> _year_month_delta_from_elements({'years': 2, 'months': 14})
    (3, 2)
    """
    return divmod(
        (int(elements.get('years', 0)) * MONTHS_IN_YEAR) +
        elements.get('months', 0),
        MONTHS_IN_YEAR
    )