diff --git a/plugin/src/test/resources/ContainerSubStatementErrorAppTag.yang b/plugin/src/test/resources/ContainerSubStatementErrorAppTag.yang
new file mode 100644
index 0000000..644b890
--- /dev/null
+++ b/plugin/src/test/resources/ContainerSubStatementErrorAppTag.yang
@@ -0,0 +1,25 @@
+module ErrorAppTag {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container interface {
+        leaf ifType {
+            type enumeration {
+                enum ethernet;
+                enum atm;
+            }
+        }
+        leaf ifMTU {
+            type uint32;
+        }
+        must "ifType != 'ethernet' or " +
+             "(ifType = 'ethernet' and ifMTU = 1500)" {
+            description "An ethernet MTU must be 1500";
+            error-app-tag "An ethernet MTU must be 1500";
+        }
+        must "ifType != 'atm' or " +
+             "(ifType = 'atm' and ifMTU <= 17966 and ifMTU >= 64)" {
+            description "An atm MTU must be  64 .. 17966";
+        }
+    }
+}
diff --git a/plugin/src/test/resources/ContainerSubStatementErrorDefaultAppTag.yang b/plugin/src/test/resources/ContainerSubStatementErrorDefaultAppTag.yang
new file mode 100644
index 0000000..c265ea2
--- /dev/null
+++ b/plugin/src/test/resources/ContainerSubStatementErrorDefaultAppTag.yang
@@ -0,0 +1,24 @@
+module ErrorAppTag {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container interface {
+        leaf ifType {
+            type enumeration {
+                enum ethernet;
+                enum atm;
+            }
+        }
+        leaf ifMTU {
+            type uint32;
+        }
+        must "ifType != 'ethernet' or " +
+             "(ifType = 'ethernet' and ifMTU = 1500)" {
+            description "An ethernet MTU must be 1500";
+        }
+        must "ifType != 'atm' or " +
+             "(ifType = 'atm' and ifMTU <= 17966 and ifMTU >= 64)" {
+            description "An atm MTU must be  64 .. 17966";
+        }
+    }
+}
diff --git a/plugin/src/test/resources/ContainerSubStatementErrorMessage.yang b/plugin/src/test/resources/ContainerSubStatementErrorMessage.yang
new file mode 100644
index 0000000..4726d0c
--- /dev/null
+++ b/plugin/src/test/resources/ContainerSubStatementErrorMessage.yang
@@ -0,0 +1,25 @@
+module ErrorMessage {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container interface {
+        leaf ifType {
+            type enumeration {
+                enum ethernet;
+                enum atm;
+            }
+        }
+        leaf ifMTU {
+            type uint32;
+        }
+        must "ifType != 'ethernet' or " +
+             "(ifType = 'ethernet' and ifMTU = 1500)" {
+            description "An ethernet MTU must be 1500";
+            error-message "An ethernet MTU must be 1500";
+        }
+        must "ifType != 'atm' or " +
+             "(ifType = 'atm' and ifMTU <= 17966 and ifMTU >= 64)" {
+            description "An atm MTU must be  64 .. 17966";
+        }
+    }
+}