class_docstr: Base class for exploring graphs.
class_docstr_tok: ["Base","class","for","exploring","graphs","."]
code: def _check_sizes(self, n_size):
      err_msg = "The neighbourhood size must be a list of non-negative integers."
      if not isinstance(n_size, list):
          self._raise_error(err_msg)
      if len(n_size) == 0:
          # Technically, length 0 should be okay, but by consensus it is invalid.
          self._raise_error(
              "The neighbourhood size list should not be empty."
          )
      for d in n_size:
          if type(d) != int or d < 0:
              self._raise_error(err_msg)
  
imports: import numpy
  import warnings
  from collections import defaultdict, deque
  from scipy import stats
  from scipy.special import softmax
  from ..core.schema import GraphSchema
  from ..core.graph import StellarGraph
  from ..core.utils import is_real_iterable
  from ..core.validation import require_integer_in_range, comma_sep
  from ..random import random_state
  from abc import ABC, abstractmethod
label_desc: Use image node_id 12 for calling the GraphWalk obj's underlying member method code with example usage: obj._check_sizes(n_size) without return types