code: def append_columns(
      self,
      columns: List[str],
      block_types: Union["BlockType", List["BlockType"]],
  ) -> List[int]:
      field_indexes = self._schema_manager.append_columns(
          columns, block_types
      )
      block_indexes = self._block_manager.append_fields(
          field_indexes, block_types
      )
  
      return block_indexes
  
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 8 for calling the DataManager obj's underlying member method code with example usage: obj.append_columns(columns, block_types) and returns: block_indexes