This is the GNU Radio PDU package. It contains signal processing
blocks that operate on Protocol Data Unit format messages. Many
such blocks are analogs of streaming API functionality.  To use the
pdu blocks, the Python namespace is in 'pdu', which is 
imported as:

    from gnuradio import pdu

A quick listing of the details can be found in Python after 
importing by using:

    help(pdu)
