addupStarsDistribution = (bonusDefs) => {
			if(Array.isArray(bonusDefs.starsDist)) {
				bonusDefs.starsDist[gear.stars || 0] = 1 + (bonusDefs.starsDist[gear.stars || 0] || 0);
			}
		}
Accmulate bonus from 1 piece of equipment to an existed bonus definition table.
@param {Object} bonusGears - the bonus definition table to be accmulated.
@param {Object} gear - the gear object instance equipped by the ship.
@see KC3Ship.prototype.equipmentTotalStats