class_docstr: Load proposal pipeline.
  
  Required key is "proposals". Updated keys are "proposals", "bbox_fields".
  
  Args:
      num_max_proposals (int, optional): Maximum number of proposals to load.
          If not specified, all proposals will be loaded.
class_docstr_tok: ["Load","proposal","pipeline",".","Required","key","is","``","proposals","''",".","Updated","keys","are","``","proposals","''",",","``","bbox_fields","''",".","Args",":","num_max_proposals","(","int",",","optional",")",":","Maximum","number","of","proposals","to","load",".","If","not","specified",",","all","proposals","will","be","loaded","."]
code: def __init__(self, num_max_proposals=None):
      self.num_max_proposals = num_max_proposals
  
imports: import os.path
  import mmcv
  import numpy
  import pycocotools.mask
  from mmdet.core import BitmapMasks, PolygonMasks
  from ..builder import PIPELINES
label_desc: Use image node_id 1 to create a new LoadProposals object from inherited base classes: object with example: obj = LoadProposals(num_max_proposals)