What is the nuclear equation for decay of tin-122 with the emissions of beta particles?

From the Wikipedia article in tin isotopes, it seems that tin-122 is "observationally stable", meaning that it has not been observed to decay. The article also states that it is believed to decay via beta- beta- decay, into tellurium-122. This type of decay

• if it really exists - would have to be extremely slow, if it

hasn't been observed yet. Since tellurium has 2 more protons than tin, and the total number of nucleons is the same (122), it follows that the end-product would have 2 neutrons less.