def by_permission_grant_policy_id(self,permission_grant_policy_id: str) -> PermissionGrantPolicyItemRequestBuilder:
        """
        Provides operations to manage the permissionGrantPolicies property of the microsoft.graph.policyRoot entity.
        param permission_grant_policy_id: The unique identifier of permissionGrantPolicy
        Returns: PermissionGrantPolicyItemRequestBuilder
        """
        if permission_grant_policy_id is None:
            raise TypeError("permission_grant_policy_id cannot be null.")
        from .item.permission_grant_policy_item_request_builder import PermissionGrantPolicyItemRequestBuilder

        url_tpl_params = get_path_parameters(self.path_parameters)
        url_tpl_params["permissionGrantPolicy%2Did"] = permission_grant_policy_id
        return PermissionGrantPolicyItemRequestBuilder(self.request_adapter, url_tpl_params)

        Provides operations to manage the permissionGrantPolicies property of the microsoft.graph.policyRoot entity.
        param permission_grant_policy_id: The unique identifier of permissionGrantPolicy
        Returns: PermissionGrantPolicyItemRequestBuilder
        
msgraph/generated/policies/permission_grant_policies/permission_grant_policies_request_builder.py