on
onBufferOverflow - configures an emit action on buffer overflow. Optional, defaults to suspending attempts to emit a value. Values other than BufferOverflow. SUSPEND are supported only when replay 0 or extraBufferCapacity 0. Buffer overflow can happen only when there is at least one subscriber that is not ready to accept the new value. In the absence of subscribers only the most recent replay values are stored and the buffer overflow behavior is never triggered and has no effect.
Default value is DEFAULT_ON_BUFFER_OVERFLOW