diff --git a/runtime/src/test/resources/yobTestYangFiles/simple-data-types.yang b/runtime/src/test/resources/yobTestYangFiles/simple-data-types.yang
index 599649f..1267a0a 100644
--- a/runtime/src/test/resources/yobTestYangFiles/simple-data-types.yang
+++ b/runtime/src/test/resources/yobTestYangFiles/simple-data-types.yang
@@ -1,275 +1,606 @@
 module simple-data-types {
-  namespace "simple:data:types";  
+    namespace "simple:data:types";
 
-  prefix "smpdtp";
-  revision 2013-11-12 {
-  }
+    prefix "smpdtp";
 
-  identity iden {
-  }
-
-  typedef tpdfempty {
-    type empty;
-  }
-
-  typedef tpdfbit {
-     type bits {
-        bit b1;
-        bit b2;
-        bit b3;
+    import YtbDataTypes {
+        prefix ytb;
     }
-  }
-
-  typedef tpdfun4 {
-    type boolean;
-  }
-
-  typedef tpdfun3 {
-    type union {
-        type tpdfbit;
-        type tpdfempty;
-    }
-  }
-
-  typedef tpdfun2 {
-    type union {
-        type tpdfun3;
-        type tpdfun4;
-    }
-  }
-
-  typedef tpdfun1 {
-    type union {
-        type uint8;
-        type decimal64 {
-            fraction-digits 2;
-        }
-    }
-  }
-
-  typedef tpdfun0 {
-     type enumeration {
-        enum "successful exit" {
-            value 1;
-        }
-        enum "grace period expired" {
-            value 2;
-        }
-     }
-  }
-
-  container cont {
-     leaf lfnint8Min {
-        type int8;
-      }
-      leaf lfnint8Max {
-        type int8;
-      }
-      leaf lfnint16Min {
-        type int16;
-      }
-      leaf lfnint16Max {
-        type int16;
-      }
-      leaf lfnint32Min {
-        type int32;
-      }
-      leaf lfnint32Max {
-        type int32;
-      }
-      leaf lfnint64Min {
-        type int64;
-      }
-      leaf lfnint64Max {
-        type int64;
-      }
-      leaf lfnuint8Max {
-        type uint8;
-      }
-      leaf lfnuint16Max {
-        type uint16;
-      }
-      leaf lfnuint32Max {
-        type uint32;
-      }
-      leaf lfuint64Max {
-        type uint64;
-      }
-      leaf lfstr {
-        type string;
-      }
-      leaf lfstr1 {
-        type string;
-      }
-      leaf lfbool1 {
-        type boolean;
-      }
-      leaf lfbool2 {
-        type boolean;
-      }
-      leaf lfbool3 {
-        type boolean;
-      }
-      leaf lfdecimal1 {
-        type decimal64 {
-            fraction-digits 1;
-        }
-      }
-      leaf lfdecimal2 {
-        type decimal64 {
-            fraction-digits 2;
-        }
-      }
-      leaf lfdecimal3 {
-        type decimal64 {
-            fraction-digits 3;
-        }
-      }
-
-      leaf lfdecimal4 {
-        type decimal64 {
-            fraction-digits 4;
-        }
-      }
-
-      leaf lfdecimal6 {
-        type decimal64 {
-            fraction-digits 6;
-        }
-      }
-
-    leaf lfenum {
-      type enumeration {
-        enum enum1;
-        enum enum2;
-        enum enum3;
-        enum enum4;
-      }
+    revision 2013-11-12 {
     }
 
-    leaf lfbits {
-      type bits {
-        bit bit1;
-        bit bit2;
-        bit bit3;
-        bit bit4;
-      }
+    identity iden {
     }
 
-    leaf lfbinary {
-        type binary;
-    }  
-
-    leaf lfref1 {                  //reference to string type
-        type leafref {
-            path "../lfstr";
-        }
+    identity val {
+        base iden;
     }
 
-    leaf lfref2 {                  //reference to number type
-        type leafref {
-            path "../lfnint8Max";
-        }
+    identity pro {
+        base iden;
     }
 
-    leaf lfempty {
+    typedef tpdfempty {
         type empty;
     }
 
-    leaf lfunion1 {
-        type union {
-            type uint16;
-            type string;
+    typedef tpdfbit {
+        type bits {
+            bit b1;
+            bit b2;
+            bit b3;
         }
     }
-    leaf lfunion2 {
+
+    typedef tpdfun4 {
+        type boolean;
+    }
+
+    typedef tpdfun3 {
         type union {
+            type tpdfbit;
+            type tpdfempty;
+        }
+    }
+
+    typedef tpdfun2 {
+        type union {
+            type tpdfun3;
+            type tpdfun4;
+        }
+    }
+
+    typedef tpdfun1 {
+        type union {
+            type uint8;
             type decimal64 {
                 fraction-digits 2;
             }
-            type string;
         }
     }
 
-    leaf lfunion4 {
-        type union {
-            type boolean;
-            type string;
-        }
-    }
-
-    leaf lfunion5 {
-        type union {
-            type uint16;
-            type string;
-        }
-    }
-
-    leaf lfunion7 {
-        type tpdfun3;
-    }
-
-    leaf lfunion8 {
-        type union {
-            type uint16;
-            type string;
-        }
-    }
-
-    leaf lfunion9 {
-        type union {
-            type uint16;
-            type boolean;
-        }
-    }
-
-    leaf lfunion10 {
-        type union {
-            type bits {
-                bit bt1;
-                bit bt2;
+    typedef tpdfun0 {
+        type enumeration {
+            enum "successful exit" {
+                value 1;
             }
-            type boolean;
+            enum "grace period expired" {
+                value 2;
+            }
         }
     }
 
-    leaf lfunion11 {
-        type union {
-            type tpdfun1;
+    container cont {
+        leaf lfnint8Min {
+            type int8;
+        }
+
+        leaf lfnint8Max {
+            type int8;
+        }
+
+        leaf lfnint16Min {
+            type int16;
+        }
+
+        leaf lfnint16Max {
+            type int16;
+        }
+
+        leaf lfnint32Min {
+            type int32;
+        }
+
+        leaf lfnint32Max {
+            type int32;
+        }
+
+        leaf lfnint64Min {
+            type int64;
+        }
+
+        leaf lfnint64Max {
+            type int64;
+        }
+
+        leaf lfnuint8Max {
+            type uint8;
+        }
+
+        leaf lfnuint16Max {
+            type uint16;
+        }
+
+        leaf lfnuint32Max {
+            type uint32;
+        }
+
+        leaf lfuint64Max {
+            type uint64;
+        }
+
+        leaf lfstr {
+            type string;
+        }
+
+        leaf lfstr1 {
+            type string;
+        }
+
+        leaf lfbool1 {
+            type boolean;
+        }
+
+        leaf lfbool2 {
+            type boolean;
+        }
+
+        leaf lfbool3 {
+            type boolean;
+        }
+
+        leaf lfdecimal1 {
+            type decimal64 {
+                fraction-digits 1;
+            }
+        }
+
+        leaf lfdecimal2 {
+            type decimal64 {
+                fraction-digits 2;
+            }
+        }
+
+        leaf lfdecimal3 {
+            type decimal64 {
+                fraction-digits 3;
+            }
+        }
+
+        leaf lfdecimal4 {
+            type decimal64 {
+                fraction-digits 4;
+            }
+        }
+
+        leaf lfdecimal6 {
+            type decimal64 {
+                fraction-digits 6;
+            }
+        }
+
+        leaf lfenum {
+            type enumeration {
+                enum enum1;
+                enum enum2;
+                enum enum3;
+                enum enum4;
+            }
+        }
+
+        leaf lfbits {
+            type bits {
+                bit bit1;
+                bit bit2;
+                bit bit3;
+                bit bit4;
+            }
+        }
+
+        leaf lfbinary {
+            type binary;
+        }
+
+        leaf lfref1 {                  //reference to string type
+            type leafref {
+                path "../lfstr";
+            }
+        }
+
+        leaf lfref2 {                  //reference to number type
+            type leafref {
+                path "../lfnint8Max";
+            }
+        }
+
+        leaf lfempty {
+            type empty;
+        }
+
+        leaf lfunion1 {
+            type union {
+                type uint16;
+                type string;
+            }
+        }
+        leaf lfunion2 {
+            type union {
+                type decimal64 {
+                    fraction-digits 2;
+                }
+                type string;
+            }
+        }
+
+        leaf lfunion4 {
+            type union {
+                type boolean;
+                type string;
+            }
+        }
+
+        leaf lfunion5 {
+            type union {
+                type uint16;
+                type string;
+            }
+        }
+
+        leaf lfunion7 {
+            type tpdfun3;
+        }
+
+        leaf lfunion8 {
+            type union {
+                type uint16;
+                type string;
+            }
+        }
+
+        leaf lfunion9 {
+            type union {
+                type uint16;
+                type boolean;
+            }
+        }
+
+        leaf lfunion10 {
+            type union {
+                type bits {
+                    bit bt1;
+                    bit bt2;
+                }
+                type boolean;
+            }
+        }
+
+        leaf lfunion11 {
+            type union {
+                type tpdfun1;
+                type tpdfun2;
+            }
+        }
+
+        leaf lfunion12 {
             type tpdfun2;
         }
-    }
 
-    leaf lfunion12 {
-        type tpdfun2;
-    }
+        leaf lfunion13 {
+            type tpdfbit;
+        }
 
-    leaf lfunion13 {
-        type tpdfbit;    
-    }
-
-    leaf lfunion14 {
-        type union {
-            type enumeration {
-                enum zero;
-                enum one;
+        leaf lfunion14 {
+            type union {
+                type enumeration {
+                    enum zero;
+                    enum one;
+                }
+                type uint16;
             }
-            type uint16;
+        }
+
+        leaf identityref1 {
+            type identityref {
+                base iden;
+            }
+        }
+
+        leaf lfenum1 {
+            type tpdfun0;
+        }
+
+        leaf inst-iden {
+            type instance-identifier;
+        }
+
+        leaf lref1 {
+            type leafref {
+                path "../lfnint8Min";
+            }
+        }
+
+        leaf lref2 {
+            type leafref {
+                path "../identityref1";
+            }
+        }
+
+        leaf lref3 {
+            type leafref {
+                path "../lfunion14";
+            }
+        }
+
+        leaf lref4 {
+            type leafref {
+                path "../lfunion13";
+            }
+        }
+
+        leaf lref5 {
+            type leafref {
+                path "../lfunion11";
+            }
+        }
+
+        leaf lref6 {
+            type leafref {
+                path "../lfref2";
+            }
+        }
+
+        leaf lref7 {
+            type leafref {
+                path "../lfenum";
+            }
+        }
+
+        leaf lref8 {
+            type leafref {
+                path "../lfdecimal6";
+            }
+        }
+
+        leaf lref9 {
+            type leafref {
+                path "/ytb:leaf12";
+            }
+        }
+
+        leaf lref10 {
+            type leafref {
+                path "/ytb:leaf11";
+            }
+        }
+
+        leaf lref11 {
+            type leafref {
+                path "/ytb:leaf10";
+            }
+        }
+
+        leaf lref12 {
+            type leafref {
+                path "/ytb:leaf9";
+            }
+        }
+
+        leaf lref13 {
+            type leafref {
+                path "/ytb:leaf8";
+            }
+        }
+
+        leaf lref14 {
+            type leafref {
+                path "/ytb:leaf7";
+            }
+        }
+
+        leaf lref15 {
+            type leafref {
+                path "/ytb:leaf6";
+            }
+        }
+
+        leaf lref16 {
+            type leafref {
+                path "/ytb:leaf5";
+            }
+        }
+
+        leaf lref17 {
+            type leafref {
+                path "/ytb:leaf4";
+            }
+        }
+
+        leaf lref18 {
+            type leafref {
+                path "/ytb:leaf3";
+            }
+        }
+
+        leaf lref19 {
+            type leafref {
+                path "/ytb:leaf2";
+            }
+        }
+
+        leaf lref20 {
+            type leafref {
+                path "/ytb:leaf1";
+            }
+        }
+
+        leaf iref1 {
+            type identityref {
+                base iden;
+            }
+        }
+
+        leaf-list iref2 {
+            type identityref {
+                base iden;
+            }
+        }
+
+        leaf iref3 {
+            type identityref {
+                base ytb:type;
+            }
+        }
+
+        leaf-list iref4 {
+            type identityref {
+                base ytb:type;
+            }
+        }
+
+        uses gr;
+    }
+
+    grouping gr {
+        container cont3 {
+            leaf-list llref1 {
+                type leafref {
+                    path "../../lfnint8Min";
+                }
+            }
+
+            leaf-list llref2 {
+                type leafref {
+                    path "../../identityref1";
+                }
+            }
+
+            leaf-list llref3 {
+                type leafref {
+                    path "../../lfunion14";
+                }
+            }
+
+            leaf-list llref4 {
+                type leafref {
+                    path "../../lfunion13";
+                }
+            }
+
+            leaf-list llref5 {
+                type leafref {
+                    path "../../lfunion11";
+                }
+            }
+
+            leaf-list llref6 {
+                type leafref {
+                    path "../../lfref2";
+                }
+            }
+
+            leaf-list llref7 {
+                type leafref {
+                    path "../../lfenum";
+                }
+            }
+
+            leaf-list llref8 {
+                type leafref {
+                    path "../../lfdecimal6";
+                }
+            }
+
+            leaf-list llref9 {
+                type leafref {
+                    path "/ytb:leaf12";
+                }
+            }
+
+            leaf-list llref10 {
+                type leafref {
+                    path "/ytb:leaf11";
+                }
+            }
+
+            leaf-list llref11 {
+                type leafref {
+                    path "/ytb:leaf10";
+                }
+            }
+
+            leaf-list llref12 {
+                type leafref {
+                    path "/ytb:leaf9";
+                }
+            }
+
+            leaf-list llref13 {
+                type leafref {
+                    path "/ytb:leaf8";
+                }
+            }
+
+            leaf-list llref14 {
+                type leafref {
+                    path "/ytb:leaf7";
+                }
+            }
+
+            leaf-list llref15 {
+                type leafref {
+                    path "/ytb:leaf6";
+                }
+            }
+
+            leaf-list llref16 {
+                type leafref {
+                    path "/ytb:leaf5";
+                }
+            }
+
+            leaf-list llref17 {
+                type leafref {
+                    path "/ytb:leaf4";
+                }
+            }
+
+            leaf-list llref18 {
+                type leafref {
+                    path "/ytb:leaf3";
+                }
+            }
+
+            leaf-list llref19 {
+                type leafref {
+                    path "/ytb:leaf2";
+                }
+            }
+
+            leaf-list llref20 {
+                type leafref {
+                    path "/ytb:leaf1";
+                }
+            }
+
+            leaf lref21 {
+                type leafref {
+                    path "/ytb:leaf1";
+                }
+            }
+
+            leaf iref1 {
+                type identityref {
+                    base iden;
+                }
+            }
+
+            leaf-list iref2 {
+                type identityref {
+                    base iden;
+                }
+            }
+
+            leaf iref3 {
+                type identityref {
+                    base ytb:type;
+                }
+            }
+
+            leaf-list iref4 {
+                type identityref {
+                    base ytb:type;
+                }
+            }
         }
     }
-
-    leaf identityref1 {
-        type identityref {
-            base iden;
-        }
-    }
-
-    leaf lfenum1 {
-        type tpdfun0;
-    }
-
-    leaf inst-iden {
-        type instance-identifier;
-    }
-  }
 }