code: def _verify_terraform():
      if not util.which("terraform"):
          raise remotelib.OperationError(
              "Terraform is required for this operation - refer to "
              "https://www.terraform.io/intro/getting-started/install.html "
              "for more information."
          )
  
imports: import json
  import logging
  import os
  import re
  import subprocess
  import sys
  from guild import remote
  from guild import remote_util
  from guild import util
  from guild import var
  from .None import ssh
  from .None import ssh_util
label_desc: Use image node_id 9 for calling the AzureVMRemote obj's underlying member method code with example usage: obj._verify_terraform() without return types