Index: /trunk/src/org/openstreetmap/josm/data/validation/TestError.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/TestError.java	(revision 11129)
+++ /trunk/src/org/openstreetmap/josm/data/validation/TestError.java	(revision 11130)
@@ -139,5 +139,5 @@
          */
         public Builder primitives(Collection<? extends OsmPrimitive> primitives) {
-            CheckParameterUtil.ensureThat(this.primitives != null, "primitives already set");
+            CheckParameterUtil.ensureThat(this.primitives == null, "primitives already set");
             this.primitives = primitives;
             return this;
@@ -163,5 +163,5 @@
          */
         public Builder highlight(Collection<? extends OsmPrimitive> highlighted) {
-            CheckParameterUtil.ensureThat(this.highlighted != null, "highlighted already set");
+            CheckParameterUtil.ensureThat(this.highlighted == null, "highlighted already set");
             this.highlighted = highlighted;
             return this;
@@ -176,5 +176,5 @@
          */
         public Builder highlightWaySegments(Collection<WaySegment> highlighted) {
-            CheckParameterUtil.ensureThat(this.highlighted != null, "highlighted already set");
+            CheckParameterUtil.ensureThat(this.highlighted == null, "highlighted already set");
             this.highlighted = highlighted;
             return this;
@@ -189,5 +189,5 @@
          */
         public Builder highlightNodePairs(Collection<List<Node>> highlighted) {
-            CheckParameterUtil.ensureThat(this.highlighted != null, "highlighted already set");
+            CheckParameterUtil.ensureThat(this.highlighted == null, "highlighted already set");
             this.highlighted = highlighted;
             return this;
@@ -201,5 +201,5 @@
          */
         public Builder fix(Supplier<Command> fixingCommand) {
-            CheckParameterUtil.ensureThat(this.fixingCommand != null, "fixingCommand already set");
+            CheckParameterUtil.ensureThat(this.fixingCommand == null, "fixingCommand already set");
             this.fixingCommand = fixingCommand;
             return this;