code: def filter_belief():
      
      if request.method == 'OPTIONS':
          return {}
      response = request.body.read().decode('utf-8')
      body = json.loads(response)
      stmts_json = body.get('statements')
      belief_cutoff = body.get('belief_cutoff')
      if belief_cutoff is not None:
          belief_cutoff = float(belief_cutoff)
      stmts = stmts_from_json(stmts_json)
      stmts_out = ac.filter_belief(stmts, belief_cutoff)
      return _return_stmts(stmts_out)
docs: Filter to beliefs above a given threshold.