title: How to know if I2C bus is busy in Multi master environment?
body: <p>Assuming an I2C network with multiple masters connected and some slaves.
  A master is already communicating with an particular slave.
  Now if the other master wants to initiate communication by sending some slave address in bus., then how would the new master come to know that the bus is already busy and it should wait until it gets freed up?</p>