code: def label_is_null(input_label):
      """Check if the label is null for different possible input types."""
      if input_label is None:
          return True
      if is_sequence_not_str(input_label):
          if len(input_label) == 0:
              return True
          if isinstance(input_label, pd.Series):
              first_element = input_label.iloc[0]
          else:
              first_element = input_label[0]
  
          if is_sequence_not_str(first_element):
              return all(pd.isnull(x).all() for x in input_label)
          else:
              return all(pd.isnull(x) for x in input_label)
      else:
          return False
  
imports: import collections
  from typing import TYPE_CHECKING, Any, Dict, List, NamedTuple, Optional, Sequence, Set, Tuple, Type, cast
  import numpy
  import pandas
  from deepchecks.core.errors import DeepchecksValueError, ValidationError
  from deepchecks.nlp.task_type import TaskType, TTextLabel
  from deepchecks.utils.logger import get_logger
  from deepchecks.utils.metrics import is_label_none
  from deepchecks.utils.type_inference import infer_categorical_features, infer_numerical_features
  from deepchecks.utils.validation import is_sequence_not_str
label_desc: Use image node_id 3 for calling a global function with example usage: label_is_null(input_label) and returns: True, False, True, all, all