code: def _validate(self):
          
          try:
              out = self._run_tf('version')
          except:
              raise Exception('ERROR: executing \'%s version\' failed; is '
                              'terraform installed and is the path to it (%s) '
                              'correct?' % (self.tf_path, self.tf_path))
          res = re.search(r'Terraform v(\d+)\.(\d+)\.(\d+)', out)
          if res is None:
              logger.error('Unable to determine terraform version; will not '
                           'validate config. Note that this may cause problems '
                           'when using older Terraform versions. This program '
                           'requires Terraform >= 0.6.16.')
              return
          self.tf_version = (
              int(res.group(1)), int(res.group(2)), int(res.group(3))
          )
          logger.debug('Terraform version: %s', self.tf_version)
          if self.tf_version < (0, 6, 16):
              raise Exception('This program requires Terraform >= 0.6.16, as '
                              'that version introduces a bug fix for working '
                              'with api_gateway_integration_response resources; '
                              'see: https://github.com/hashicorp/terraform/pull'
                              '/5893')
          try:
              self._run_tf('validate', ['.'])
          except Exception as ex:
              logger.critical("Terraform config validation failed. "
                              "This is almost certainly a bug in "
                              "webhook2lambda2sqs; please re-run with '-vv' and "
                              "open a bug at <https://github.com/jantman/"
                              "webhook2lambda2sqs/issues>. Exception: %s", ex)
              raise Exception(
                  'ERROR: Terraform config validation failed: %s' % ex
              )
docs: Confirm that we can run terraform (by calling its version action)
          and then validate the configuration.