+public sealed interface YangExpr extends Immutable, Serializable
+ permits YangBinaryExpr,
+ YangConstantExpr,
+ YangFilterExpr,
+ YangFunctionCallExpr,
+ YangLiteralExpr,
+ YangLocationPath,
+ YangNaryExpr,
+ YangNegateExpr,
+ YangNumberExpr,
+ YangPathExpr,
+ YangQNameExpr,
+ YangVariableReferenceExpr {