def __init__(self, view_builder=None):
        if view_builder:
            self._view_builder = view_builder
        elif self._view_builder_class:
            self._view_builder = self._view_builder_class()
        else:
            self._view_builder = None
convert anchor file to 12 col blast file
dataset/ETHPy150Open openstack/rack/rack/api/wsgi.py/Controller.__init__--crossover with--dataset/ETHPy150Open tanghaibao/jcvi/compara/synteny.py/AnchorFile.blast