def __init__(self, base, dest):
    self.base = os.path.abspath(os.path.join(get_buildroot(), base))
    if not os.path.isdir(self.base):
      raise DirectoryReMapper.NonexistentBaseError(
        'Could not find a directory to bundle relative to {0}'.format(self.base))
    self.dest = dest
The base directory files should be mapped from, and the dest they should be mapped to.
dataset/ETHPy150Open pantsbuild/pants/src/python/pants/backend/jvm/targets/jvm_app.py/DirectoryReMapper.__init__