class_docstr: Creates new connection to Salesforce and allows you to pull data out of SFDC and save it to a file.
  
  You can then use that file with other Airflow operators to move the data into another data source.
  
  :param conn_id: The name of the connection that has the parameters needed to connect to Salesforce.
      The connection should be of type `Salesforce`.
  :param session_id: The access token for a given HTTP request session.
  :param session: A custom HTTP request session. This enables the use of requests Session features not
      otherwise exposed by `simple_salesforce`.
  
  .. note::
      A connection to Salesforce can be created via several authentication options:
  
      * Password: Provide Username, Password, and Security Token
      * Direct Session: Provide a `session_id` and either Instance or Instance URL
      * OAuth 2.0 JWT: Provide a Consumer Key and either a Private Key or Private Key File Path
      * IP Filtering: Provide Username, Password, and an Organization ID
  
      If in sandbox, enter a Domain value of 'test'.
docstr: Get field from extra, first checking short name, then for backcompat we check for prefixed name.
docstr_tok: ["Get","field","from","extra",",","first","checking","short","name",",","then","for","backcompat","we","check","for","prefixed","name","."]
code: def _get_field(self, extras: dict, field_name: str):
      """Get field from extra, first checking short name, then for backcompat we check for prefixed name."""
      backcompat_prefix = "extra__salesforce__"
      if field_name.startswith("extra__"):
          raise ValueError(
              f"Got prefixed name {field_name}; please remove the '{backcompat_prefix}' prefix "
              "when using this method."
          )
      if field_name in extras:
          return extras[field_name] or None
      prefixed_name = f"{backcompat_prefix}{field_name}"
      return extras.get(prefixed_name) or None
  
imports: from __future__ import annotations
  import logging
  import time
  from functools import cached_property
  from typing import TYPE_CHECKING, Any, Iterable
  from simple_salesforce import Salesforce, api
  from airflow.hooks.base import BaseHook
label_desc: Use image node_id 2 for calling the SalesforceHook obj's underlying member method code with example usage: obj._get_field(extras, field_name) and returns: unknown, unknown