class_docstr: Corpus reader for the York-Toronto-Helsinki Parsed Corpus of Old
  English Prose (YCOE), a 1.5 million word syntactically-annotated
  corpus of Old English prose texts.
class_docstr_tok: ["Corpus","reader","for","the","York-Toronto-Helsinki","Parsed","Corpus","of","Old","English","Prose","(","YCOE",")",",","a","1.5","million","word","syntactically-annotated","corpus","of","Old","English","prose","texts","."]
docstr: Helper that selects the appropriate fileids for a given set of
  documents from a given subcorpus (pos or psd).
docstr_tok: ["Helper","that","selects","the","appropriate","fileids","for","a","given","set","of","documents","from","a","given","subcorpus","(","pos","or","psd",")","."]
code: def _getfileids(self, documents, subcorpus):
      """
      Helper that selects the appropriate fileids for a given set of
      documents from a given subcorpus (pos or psd).
      """
      if documents is None:
          documents = self._documents
      else:
          if isinstance(documents, str):
              documents = [documents]
          for document in documents:
              if document not in self._documents:
                  if document[-4:] in (".pos", ".psd"):
                      raise ValueError(
                          "Expected a document identifier, not a file "
                          "identifier.  (Use corpus.documents() to get "
                          "a list of document identifiers."
                      )
                  else:
                      raise ValueError(
                          "Document identifier %s not found" % document
                      )
      return [f"{d}.{subcorpus}" for d in documents]
  
imports: import os
  import re
  from nltk.corpus.reader.api import *
  from nltk.corpus.reader.bracket_parse import BracketParseCorpusReader
  from nltk.corpus.reader.tagged import TaggedCorpusReader
  from nltk.corpus.reader.util import *
  from nltk.tokenize import RegexpTokenizer
label_desc: Use image node_id 4 for calling the YCOECorpusReader obj's underlying member method code with example usage: obj._getfileids(documents, subcorpus) and returns: unknown