'This method returns the holes associated with a blob as a list of tuples.'

def _getHoles(self, seq):

    retVal = None
    holes = seq.v_next()
    if (holes is not None):
        retVal = [list(holes)]
        while (holes.h_next() is not None):
            holes = holes.h_next()
            temp = list(holes)
            if (len(temp) >= 3):
                retVal.append(temp)
    return retVal
