code: def read_block(self, stream):
      sentence = []
      sentences = []
      space = False
      no_space = False
  
      tags = set()
  
      lines = self._read_data(stream)
  
      while True:
          # we may have only part of last line
          if len(lines) <= 1:
              self._seek(stream)
              lines = self._read_data(stream)
  
          if lines == [""]:
              assert not sentences
              return []
  
          line = lines.pop()
          self.position += len(line) + 1
  
          if line.startswith('<chunk type="s"'):
              self.in_sentence = True
          elif line.startswith('<chunk type="p"'):
              pass
          elif line.startswith("<tok"):
              if self.append_space and space and not no_space:
                  self._append_space(sentence)
              space = True
              no_space = False
              orth = ""
              tags = set()
          elif line.startswith("</chunk"):
              if self.in_sentence:
                  self.in_sentence = False
                  self._seek(stream)
                  if self.mode == self.SENTS_MODE:
                      return [sentence]
                  elif self.mode == self.WORDS_MODE:
                      if self.append_space:
                          self._append_space(sentence)
                      return sentence
                  else:
                      sentences.append(sentence)
              elif self.mode == self.PARAS_MODE:
                  self._seek(stream)
                  return [sentences]
          elif line.startswith("<orth"):
              orth = line[6:-7]
              if self.replace_xmlentities:
                  orth = orth.replace("&quot;", '"').replace(
                      "&amp;", "&"
                  )
          elif line.startswith("<lex"):
              if not self.disamb_only or line.find("disamb=") != -1:
                  tag = line[
                      line.index("<ctag") + 6 : line.index("</ctag")
                  ]
                  tags.add(tag)
          elif line.startswith("</tok"):
              if self.show_tags:
                  if self.simplify_tags:
                      tags = [t.split(":")[0] for t in tags]
                  if not self.one_tag or not self.disamb_only:
                      sentence.append((orth, tuple(tags)))
                  else:
                      sentence.append((orth, tags.pop()))
              else:
                  sentence.append(orth)
          elif line.startswith("<ns/>"):
              if self.append_space:
                  no_space = True
              if self.append_no_space:
                  if self.show_tags:
                      sentence.append(("", "no-space"))
                  else:
                      sentence.append("")
          elif line.startswith("</cesAna"):
              pass
  
imports: import functools
  from nltk.corpus.reader.api import CorpusReader
  from nltk.corpus.reader.util import StreamBackedCorpusView, concat
label_desc: Use image node_id 2 for calling the IPIPANCorpusView obj's underlying member method code with example usage: obj.read_block(stream) and returns: list, list, list, sentence