I am using several i2c libraries from various brilliant people who have solved my problems for me :-)
each of these libs presumably does a Wire.begin, somewhere in its depths.
so my question is this: if Wire.begin has already been called, what happens when it is called again?
does the 2nd call erase and overwrite the first?
in other words -- suppose I want to venture into the exciting new world of multi-master i2c, I need to do a Wire.begin(address) call; if I then later in setup invoke, say, the Adafruit LCD matrix I2c backpack library, I'm guessing that it does a Wire.begin() (bus master init). Would this override my earlier Wire.begin(address)? Or do subsequent Wire.begin's safely "do nothing if already connected"?