class_docstr: Check if there are columns which have only a single unique value in all rows.
  
  Parameters
  ----------
  columns : Union[Hashable, List[Hashable]] , default: None
      Columns to check, if none are given checks all
      columns except ignored ones.
  ignore_columns : Union[Hashable, List[Hashable]] , default: None
      Columns to ignore, if none given checks based
      on columns variable.
  ignore_nan : bool, default True
      Whether to ignore NaN values in a column when counting the number of unique values.
  n_samples : int , default: 10_000_000
      number of samples to use for this check.
  random_state : int, default: 42
      random seed for all check internals.
docstr: Add condition - no column contains only a single value.
code: def add_condition_not_single_value(self):
      """Add condition - no column contains only a single value."""
      name = "Does not contain only a single value"
  
      def condition(result):
          single_value_cols = [k for k, v in result.items() if v == 1]
          if single_value_cols:
              details = (
                  f"Found {len(single_value_cols)} out of {len(result)} columns with a single value: "
                  f"{single_value_cols}"
              )
              return ConditionResult(ConditionCategory.FAIL, details)
          else:
              return ConditionResult(
                  ConditionCategory.PASS,
                  get_condition_passed_message(result),
              )
  
      return self.add_condition(name, condition)
  
file_path: deepchecks/deepchecks/tabular/checks/data_integrity/is_single_value.py
imports: from typing import List, Union
  import pandas
  from deepchecks.core import CheckResult, ConditionCategory, ConditionResult
  from deepchecks.tabular import Context, SingleDatasetCheck
  from deepchecks.tabular.utils.messages import get_condition_passed_message
  from deepchecks.utils.dataframes import select_from_dataframe
  from deepchecks.utils.typing import Hashable
label_desc: Use image node_id 3 for calling the IsSingleValue obj's underlying member method code with example usage: obj.add_condition_not_single_value() and returns: self, ConditionResult, ConditionResult