def set_last_col_idx(self, last_col_idx):
		'''
		Parameters
		----------
		param last_col_idx : int
			number of columns
		'''
		assert last_col_idx >= self._max_col
		self._max_col = last_col_idx
		return self

		Parameters
		----------
		param last_col_idx : int
			number of columns
		
scattertext/CSRMatrixTools.py