code: def _validate_label_map(label_map):
      """Checks if a label map is valid.
  
      Args:
        label_map: StringIntLabelMap to validate.
  
      Raises:
        ValueError: if label map is invalid.
      """
      for item in label_map.item:
          if item.id < 1:
              raise ValueError("Label map ids should be >= 1.")
  
file_path: SlowFast/ava_evaluation/label_map_util.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
label_desc: Use image node_id 1 for calling a global function with example usage: _validate_label_map(label_map) without return types