The contribution of this port to the path cost (in 32
bits value) of paths towards the spanning tree root which
include this port.
This object is used to configure the spanning tree port
path cost in 32 bits value range when the
stpxSpanningTreePathCostOperMode is long(2).
If the stpxSpanningTreePathCostOperMode is short(1), this
MIB object is not instantiated.