code: def nextline(self):
      if self.iline >= len(self.lines):
          raise StopIteration
      line = self.lines[self.iline]
      self.iline += 1
      return line
  
file_path: chainer/docs/source/_docstring_check.py
imports: import math
label_desc: Use image node_id 2 for calling the DocstringCheckContext obj's underlying member method code with example usage: obj.nextline() and returns: line