class_docstr: A 'view' of a corpus file that joins together one or more
  ``StreamBackedCorpusViews<StreamBackedCorpusView>``.  At most
  one file handle is left open at any time.
class_docstr_tok: ["A","'view","'","of","a","corpus","file","that","joins","together","one","or","more","``","StreamBackedCorpusViews","<","StreamBackedCorpusView",">","``",".","At","most","one","file","handle","is","left","open","at","any","time","."]
code: def iterate_from(self, start_tok):
      piecenum = bisect.bisect_right(self._offsets, start_tok) - 1
  
      while piecenum < len(self._pieces):
          offset = self._offsets[piecenum]
          piece = self._pieces[piecenum]
  
          # If we've got another piece open, close it first.
          if self._open_piece is not piece:
              if self._open_piece is not None:
                  self._open_piece.close()
              self._open_piece = piece
  
          # Get everything we can from this piece.
          yield from piece.iterate_from(max(0, start_tok - offset))
  
          # Update the offset table.
          if piecenum + 1 == len(self._offsets):
              self._offsets.append(self._offsets[-1] + len(piece))
  
          # Move on to the next piece.
          piecenum += 1
  
imports: import bisect
  import os
  import pickle
  import re
  import tempfile
  from functools import reduce
  from xml.etree import ElementTree
  from nltk.data import FileSystemPathPointer, PathPointer, SeekableUnicodeStreamReader, ZipFilePathPointer
  from nltk.internals import slice_bounds
  from nltk.tokenize import wordpunct_tokenize
  from nltk.util import AbstractLazySequence, LazyConcatenation, LazySubsequence
label_desc: Use image node_id 4 for calling the ConcatenatedCorpusView obj's underlying member method code with example usage: obj.iterate_from(start_tok) without return types