code: def needs_filling(self):
      for indexer in self.indexers.values():
          # FIXME: cache results of indexer == -1 checks.
          if (indexer == -1).any():
              return True
  
      return False
  
imports: from collections import defaultdict
  import copy
  import numpy
  from pandas._libs import internals, tslibs
  from pandas.util._decorators import cache_readonly
  from pandas.core.dtypes.cast import maybe_promote
  from pandas.core.dtypes.common import _get_dtype, is_categorical_dtype, is_datetime64_dtype, is_datetime64tz_dtype, is_extension_array_dtype, is_float_dtype, is_numeric_dtype, is_sparse, is_timedelta64_dtype
  import pandas.core.dtypes.concat
  from pandas.core.dtypes.missing import isna
  import pandas.core.algorithms
label_desc: Use image node_id 3 for calling the JoinUnit obj's underlying member method code with example usage: obj.needs_filling() and returns: False, True