class_docstr: A wrapper around Python 3's builtin :class:`csv.DictWriter`.
class_docstr_tok: ["A","wrapper","around","Python","3","'s","builtin",":","class",":","`","csv.DictWriter","`","."]
code: def _append_line_number(self, row):
      if self.row_count == 0:
          row["line_number"] = "line_number"
      else:
          row["line_number"] = self.row_count
  
      self.row_count += 1
  
imports: import csv
  import warnings
  from agate.exceptions import FieldSizeLimitError
label_desc: Use image node_id 2 for calling the DictWriter obj's underlying member method code with example usage: obj._append_line_number(row) without return types