docstr: Get sqlite3 Connection
  
  The connection is created on the first call of this property
docstr_tok: ["Get","sqlite3","Connection","The","connection","is","created","on","the","first","call","of","this","property"]
code: def session(self):
      """Get sqlite3 Connection
  
      The connection is created on the first call of this property
      """
      try:
          return self._session
      except AttributeError:
          self._init_db()
          return self._session
  
imports: import contextlib
  import getpass
  import logging
  import os
  import sqlite3
  import tempfile
  import warnings
  from io import BytesIO
  from os.path import join
  import numpy
  from nibabel.optpkg import optional_package
  from .nifti1 import Nifti1Header
label_desc: Use image node_id 2 for calling the _DB obj's underlying member method code with example usage: obj.session() and returns: self, self