class_docstr: Single-step selection.
docstr: Select anchor nodes.
  
  .. note ::
      the number of selected anchors may be smaller than $k$, if there
      are less entities present in the edge index.
  
  :param edge_index: shape: (m, 2)
      the edge_index, i.e., adjacency list.
  
  :param known_anchors: numpy.ndarray
      an array of already known anchors for getting only unique anchors
  
  :return: (k,)
      the selected entity ids
code: def __call__(
      self,
      edge_index: numpy.ndarray,
      known_anchors: Optional[numpy.ndarray] = None,
  ) -> numpy.ndarray:
      """
      Select anchor nodes.
  
      .. note ::
          the number of selected anchors may be smaller than $k$, if there
          are less entities present in the edge index.
  
      :param edge_index: shape: (m, 2)
          the edge_index, i.e., adjacency list.
  
      :param known_anchors: numpy.ndarray
          an array of already known anchors for getting only unique anchors
  
      :return: (k,)
          the selected entity ids
      """
      return self.filter_unique(
          anchor_ranking=self.rank(edge_index=edge_index),
          known_anchors=known_anchors,
      )
  
imports: import logging
  from abc import ABC, abstractmethod
  from typing import Iterable, Optional, Sequence, Union
  import numpy
  import torch
  from class_resolver import ClassResolver, HintOrType, OptionalKwargs
  from torch_ppr import page_rank
  from ...triples.splitting import get_absolute_split_sizes, normalize_ratios
  from ...typing import OneOrSequence
  from ...utils import ExtraReprMixin
label_desc: Use image node_id 1 for calling the SingleSelection obj's underlying member method code with example usage: obj.__call__(edge_index, known_anchors) and returns: self