code: def infer_operable_blocks(self):
      operable_field_offsets = (
          self._schema_manager.infer_operable_filed_offsets()
      )
      block_index_set = set(
          self._block_manager.loc_block(offset, with_offset=False)
          for offset in operable_field_offsets
      )
      return sorted(list(block_index_set))
  
imports: import numpy
  from .schema_manager import SchemaManager
  from .block_manager import BlockManager
  from .block_manager import BlockType
  import pandas
  from ..entity import types
  from typing import Union, List, Tuple
  from ..conf.default_config import DATAFRAME_BLOCK_ROW_SIZE
label_desc: Use image node_id 23 for calling the DataManager obj's underlying member method code with example usage: obj.infer_operable_blocks() and returns: sorted