get_esn

Gets the <ulink url="http://en.

wikipedia.org/wiki/Electronic_serial_number">Electronic Serial Number</ulink>, as reported by this ModemCdma.

The ESN is superceded by MEID, but still used in older devices.

<warning>The returned value is only valid until the property changes so it is only safe to use this function on the thread where this was constructed. Use dup_esn if on another thread.</warning>

Parameters:

this	A ModemCdma.

Returns:

The ESN, or null if none available.