class_docstr: Hook for Google Cloud Spanner APIs.
  
  All the methods in the hook where project_id is used must be called with
  keyword arguments rather than positional.
class_docstr_tok: ["Hook","for","Google","Cloud","Spanner","APIs",".","All","the","methods","in","the","hook","where","project_id","is","used","must","be","called","with","keyword","arguments","rather","than","positional","."]
docstr: Extract spanner database connection parameters.
docstr_tok: ["Extract","spanner","database","connection","parameters","."]
code: def _get_conn_params(self) -> SpannerConnectionParams:
      """Extract spanner database connection parameters."""
      extras = self.get_connection(self.gcp_conn_id).extra_dejson
      project_id = get_field(extras, "project_id") or self.project_id
      instance_id = get_field(extras, "instance_id")
      database_id = get_field(extras, "database_id")
      return SpannerConnectionParams(
          project_id, instance_id, database_id
      )
  
imports: from __future__ import annotations
  from typing import TYPE_CHECKING, Callable, NamedTuple, Sequence
  from google.api_core.exceptions import AlreadyExists, GoogleAPICallError
  from google.cloud.spanner_v1.client import Client
  from sqlalchemy import create_engine
  from airflow.exceptions import AirflowException
  from airflow.providers.common.sql.hooks.sql import DbApiHook
  from airflow.providers.google.common.consts import CLIENT_INFO
  from airflow.providers.google.common.hooks.base_google import GoogleBaseHook, get_field
label_desc: Use image node_id 3 for calling the SpannerHook obj's underlying member method code with example usage: obj._get_conn_params() and returns: SpannerConnectionParams