class_docstr: A sampler that combines positive sampler and negative sampler.
code: def __init__(self, pos_sampler, neg_sampler, **kwargs):
      super(CombinedSampler, self).__init__(**kwargs)
      self.pos_sampler = build_sampler(pos_sampler, **kwargs)
      self.neg_sampler = build_sampler(neg_sampler, **kwargs)
  
imports: from ..builder import BBOX_SAMPLERS, build_sampler
  from .base_sampler import BaseSampler
label_desc: Use image node_id 1 to create a new CombinedSampler object from inherited base classes: BaseSampler with example: obj = CombinedSampler(pos_sampler, neg_sampler)