code: def bbox2array(vol, bbox, order='F', readonly=False, lock=None, location=None):
    
    location = location or vol.shared_memory_id
    shape = list(bbox.size3()) + [ vol.num_channels ]
    return ndarray(shape=shape, dtype=vol.dtype, location=location, 
      readonly=readonly, lock=lock, order=order)
docs: Convenince method for creating a 
    shared memory numpy array based on a CloudVolume
    and Bbox. c.f. sharedmemory.ndarray for information
    on the optional lock parameter.