diff --git a/modules/compiler/src/main/java/script/parser/PositionConfigureUtils.java b/modules/compiler/src/main/java/script/parser/PositionConfigureUtils.java
index 4b60f97..840ecad 100644
--- a/modules/compiler/src/main/java/script/parser/PositionConfigureUtils.java
+++ b/modules/compiler/src/main/java/script/parser/PositionConfigureUtils.java
@@ -136,6 +136,11 @@ public static <T extends ASTNode> T ast(T astNode, ASTNode start, ASTNode stop)
         return astNode;
     }
 
+    /**
+     * Get the zero-based start position (line, character) of a token.
+     *
+     * @param ctx
+     */
     public static TokenPosition tokenPosition(ParserRuleContext ctx) {
         var token = ctx.getStart();
         return new TokenPosition(
diff --git a/modules/language-server/src/main/java/nextflow/lsp/NextflowLanguageServer.java b/modules/language-server/src/main/java/nextflow/lsp/NextflowLanguageServer.java
index be8f509..a7946f7 100644
--- a/modules/language-server/src/main/java/nextflow/lsp/NextflowLanguageServer.java
+++ b/modules/language-server/src/main/java/nextflow/lsp/NextflowLanguageServer.java
@@ -172,7 +172,7 @@ public CompletableFuture<InitializeResult> initialize(InitializeParams params) {
         var semanticTokensOptions = new SemanticTokensWithRegistrationOptions(
             new SemanticTokensLegend(
                 SemanticTokensVisitor.TOKEN_TYPES,
-                List.of()
+                Collections.emptyList()
             ),
             true,
             false);
diff --git a/modules/language-server/src/main/java/nextflow/lsp/services/SemanticTokensVisitor.java b/modules/language-server/src/main/java/nextflow/lsp/services/SemanticTokensVisitor.java
index 4969596..607d7e5 100644
--- a/modules/language-server/src/main/java/nextflow/lsp/services/SemanticTokensVisitor.java
+++ b/modules/language-server/src/main/java/nextflow/lsp/services/SemanticTokensVisitor.java
@@ -108,7 +108,7 @@ public SemanticTokens getTokens() {
                 0
             ))
             .collect(Collectors.toList());
-            
+
         return new SemanticTokens(data);
     }
 
@@ -186,19 +186,17 @@ public void visitGStringExpression(GStringExpression node) {
         inGString = igs;
     }
 
-}
-
+    private static record SemanticToken(
+        Position position,
+        int length,
+        String type
+    ) {}
 
-record SemanticToken(
-    Position position,
-    int length,
-    String type
-) {}
+    private static record SemanticTokenDelta(
+        int deltaLine,
+        int deltaStartChar,
+        int length,
+        String type
+    ) {}
 
-
-record SemanticTokenDelta(
-    int deltaLine,
-    int deltaStartChar,
-    int length,
-    String type
-) {}
+}
diff --git a/modules/language-server/src/main/java/nextflow/lsp/services/config/ConfigSemanticTokensProvider.java b/modules/language-server/src/main/java/nextflow/lsp/services/config/ConfigSemanticTokensProvider.java
index c96ce2e..368d347 100644
--- a/modules/language-server/src/main/java/nextflow/lsp/services/config/ConfigSemanticTokensProvider.java
+++ b/modules/language-server/src/main/java/nextflow/lsp/services/config/ConfigSemanticTokensProvider.java
@@ -61,43 +61,43 @@ public SemanticTokens semanticTokensFull(TextDocumentIdentifier textDocument) {
     }
 
     private static class Visitor extends ConfigVisitorSupport {
-    
+
         private SourceUnit sourceUnit;
-    
+
         private SemanticTokensVisitor tok;
-    
+
         public Visitor(SourceUnit sourceUnit) {
             this.sourceUnit = sourceUnit;
             this.tok = new SemanticTokensVisitor();
         }
-    
+
         @Override
         protected SourceUnit getSourceUnit() {
             return sourceUnit;
         }
-    
+
         public void visit() {
             var moduleNode = sourceUnit.getAST();
             if( moduleNode instanceof ConfigNode cn )
                 super.visit(cn);
         }
-    
+
         public SemanticTokens getTokens() {
             return tok.getTokens();
         }
-    
+
         // config statements
-    
+
         @Override
         public void visitConfigAssign(ConfigAssignNode node) {
             tok.visit(node.value);
         }
-    
+
         @Override
         public void visitConfigInclude(ConfigIncludeNode node) {
             tok.visit(node.source);
         }
-    
+
     }
 
 }
diff --git a/modules/language-server/src/main/java/nextflow/lsp/services/script/ScriptSemanticTokensProvider.java b/modules/language-server/src/main/java/nextflow/lsp/services/script/ScriptSemanticTokensProvider.java
index 0750d6c..abbae92 100644
--- a/modules/language-server/src/main/java/nextflow/lsp/services/script/ScriptSemanticTokensProvider.java
+++ b/modules/language-server/src/main/java/nextflow/lsp/services/script/ScriptSemanticTokensProvider.java
@@ -75,36 +75,36 @@ public SemanticTokens semanticTokensFull(TextDocumentIdentifier textDocument) {
     }
 
     private static class Visitor extends ScriptVisitorSupport {
-    
+
         private SourceUnit sourceUnit;
-    
+
         private SemanticTokensVisitor tok;
-    
+
         public Visitor(SourceUnit sourceUnit) {
             this.sourceUnit = sourceUnit;
             this.tok = new SemanticTokensVisitor();
         }
-    
+
         @Override
         protected SourceUnit getSourceUnit() {
             return sourceUnit;
         }
-    
+
         public void visit() {
             var moduleNode = sourceUnit.getAST();
             if( moduleNode instanceof ScriptNode sn )
                 visit(sn);
         }
-    
+
         public SemanticTokens getTokens() {
             return tok.getTokens();
         }
-    
+
         @Override
         public void visitFeatureFlag(FeatureFlagNode node) {
             tok.visit(node.value);
         }
-    
+
         @Override
         public void visitInclude(IncludeNode node) {
             for( var module : node.modules ) {
@@ -113,33 +113,33 @@ public void visitInclude(IncludeNode node) {
                     tok.append(module.getNodeMetaData("_START_ALIAS"), module.alias, SemanticTokenTypes.Function);
             }
         }
-    
+
         @Override
         public void visitParam(ParamNode node) {
             tok.visit(node.target);
             tok.visit(node.value);
         }
-    
+
         @Override
         public void visitWorkflow(WorkflowNode node) {
             if( node.takes instanceof BlockStatement block )
                 visitWorkflowTakes(block.getStatements());
-    
+
             tok.visit(node.main);
-    
+
             if( node.emits instanceof BlockStatement block )
                 visitWorkflowEmits(block.getStatements());
-    
+
             tok.visit(node.publishers);
         }
-    
+
         protected void visitWorkflowTakes(List<Statement> takes) {
             for( var stmt : takes ) {
                 var ve = (VariableExpression) asVarX(stmt);
                 tok.append(ve, SemanticTokenTypes.Parameter);
             }
         }
-    
+
         protected void visitWorkflowEmits(List<Statement> emits) {
             for( var stmt : emits ) {
                 var es = (ExpressionStatement)stmt;
@@ -160,7 +160,7 @@ else if( emit instanceof VariableExpression ve ) {
                 }
             }
         }
-    
+
         @Override
         public void visitProcess(ProcessNode node) {
             tok.visit(node.directives);
@@ -170,30 +170,30 @@ public void visitProcess(ProcessNode node) {
             tok.visit(node.exec);
             tok.visit(node.stub);
         }
-    
+
         @Override
         public void visitFunction(FunctionNode node) {
             tok.visitParameters(node.getParameters());
             tok.visit(node.getCode());
         }
-    
+
         @Override
         public void visitEnum(ClassNode node) {
             for( var fn : node.getFields() )
                 tok.append(fn, SemanticTokenTypes.EnumMember);
         }
-    
+
         @Override
         public void visitOutput(OutputNode node) {
             visitOutputBody(node.body);
         }
-    
+
         protected void visitOutputBody(Statement body) {
             asBlockStatements(body).forEach((stmt) -> {
                 var call = asMethodCallX(stmt);
                 if( call == null )
                     return;
-    
+
                 var code = asDslBlock(call, 1);
                 if( code != null ) {
                     tok.append(call.getMethod(), SemanticTokenTypes.Parameter);
@@ -201,7 +201,7 @@ protected void visitOutputBody(Statement body) {
                 }
             });
         }
-    
+
     }
 
 }