class_docstr: Iterator for creating Quantile DMatrix from partitions.
code: def reset(self) -> None:
      self._iter = 0
  
imports: from collections import defaultdict, namedtuple
  from typing import Any, Callable, Dict, Iterator, List, Optional, Sequence, Tuple, Union
  import numpy
  import pandas
  from scipy.sparse import csr_matrix
  from xgboost import DataIter, DMatrix, QuantileDMatrix, XGBModel
  from xgboost.compat import concat
  from .._typing import ArrayLike
  from .utils import get_logger
label_desc: Use image node_id 4 for calling the PartIter obj's underlying member method code with example usage: obj.reset() without return types