docstr: Return True if label is a known label.
          
docstr_tok: ["Return","True","if","label","is","a","known","label","."]
code: def has_label(self, label):
      """Return True if label is a known label."""
      return label in self.id_to_labels
  
imports: import csv
  import json
  import os
  import warnings
  import numpy
  from PIL import Image
  from .generator import Generator
  from ..utils.image import read_image_bgr
label_desc: Use image node_id 5 for calling the OpenImagesGenerator obj's underlying member method code with example usage: obj.has_label(label) and returns: unknown