class_docstr: Metadata about the block.
class_docstr_tok: ["Metadata","about","the","block","."]
code: def __post_init__(self):
      if self.input_files is None:
          self.input_files = []
      if self.size_bytes is not None:
          # Require size_bytes to be int, ray.util.metrics objects
          # will not take other types like numpy.int64
          assert isinstance(self.size_bytes, int)
  
imports: import collections
  import os
  import time
  from dataclasses import dataclass
  from typing import TYPE_CHECKING, Callable, Dict, Iterator, List, Literal, Optional, Protocol, Tuple, TypeVar, Union
  import numpy
  import ray
  from ray import DynamicObjectRefGenerator
  from ray.data._internal.util import _check_pyarrow_version, _truncated_repr
  from ray.types import ObjectRef
  from ray.util.annotations import DeveloperAPI
  import psutil
label_desc: Use image node_id 1 for calling the BlockMetadata obj's underlying member method code with example usage: obj.__post_init__() without return types