The officers of every labor organization shall be elected for such terms, not exceeding four years, as the constitution or bylaws may provide. The election shall be by secret ballot. The constitution or bylaws may provide for multiple choice voting, nomination by primaries or runoff elections, or other method of election by which selection by a majority may be obtained. In the absence of such provision, the candidate for any office receiving the largest number of votes cast for that office shall be declared elected. It is the duty of every labor organization and the officers thereof to hold an election for the purpose of electing the successor of every such officer prior to the expiration of a term. Any employee who is elected to a full time position in a labor organization shall be given a leave of absence for the duration of time holding such office, without losing seniority or entitlement to any rights acquired as a result of employment.