def schema_root(self) -> "SchemaTreeNode":
        """Return the root node of the receiver's schema."""
        sn = self
        while sn.parent:
            sn = sn.parent
        return sn
def schema_root ( self ) -> "SchemaTreeNode" : sn = self while sn . parent : sn = sn . parent return sn
Return the root node of the receiver's schema.