after refactor - some tests are working again

src/structs/AbstractStruct.js

@@ -18,6 +18,7 @@ export class AbstractStruct {
      * @readonly
      */
     this.id = id
+    this.deleted = false
   }
   /**
    * Merge this struct with the item to the right.
@@ -35,12 +36,6 @@ export class AbstractStruct {
   get length () {
     throw error.methodUnimplemented()
   }
-  /**
-   * @type {boolean}
-   */
-  get deleted () {
-    throw error.methodUnimplemented()
-  }
   /**
    * @param {encoding.Encoder} encoder The encoder to write data to.
    * @param {number} offset
@@ -87,4 +82,10 @@ export class AbstractRef {
   toStruct (transaction) {
     throw error.methodUnimplemented()
   }
+  /**
+   * @type {number}
+   */
+  get length () {
+    return 1
+  }
 }