class_docstr: Factory class to create a csr_matrix.
          
docstr: Parameters
  ----------
  param last_row_idx : int
          number of rows
docstr_tok: ["Parameters","--","--","--","--","--","param","last_row_idx",":","int","number","of","rows"]
code: def set_last_row_idx(self, last_row_idx):
      """
      Parameters
      ----------
      param last_row_idx : int
              number of rows
      """
      assert last_row_idx >= self._max_row
      self._max_row = last_row_idx
      return self
  
file_path: scattertext/scattertext/CSRMatrixTools.py
imports: import numpy
  from scipy.sparse import csr_matrix
label_desc: Use image node_id 4 for calling the CSRMatrixFactory obj's underlying member method code with example usage: obj.set_last_row_idx(last_row_idx) and returns: self