diff --git a/validation-model/src/main/java/org/verapdf/gf/foundry/VeraFoundry.java b/validation-model/src/main/java/org/verapdf/gf/foundry/VeraFoundry.java
index 85fbc8580..cd0e9cf9b 100644
--- a/validation-model/src/main/java/org/verapdf/gf/foundry/VeraFoundry.java
+++ b/validation-model/src/main/java/org/verapdf/gf/foundry/VeraFoundry.java
@@ -58,7 +58,7 @@ public ComponentDetails getDetails() {
 	}
 
 	/**
-	 * @see org.verapdf.pdfa.VeraPDFFoundry#newPdfParser(java.io.InputStream)
+	 * @see org.verapdf.pdfa.VeraPDFFoundry#createParser(InputStream)
 	 */
 	@Override
 	public PDFAParser createParser(InputStream pdfStream) throws ModelParsingException, EncryptedPdfException {
@@ -66,8 +66,7 @@ public PDFAParser createParser(InputStream pdfStream) throws ModelParsingExcepti
 	}
 
 	/**
-	 * @see org.verapdf.pdfa.VeraPDFFoundry#newPdfParser(java.io.InputStream,
-	 *      org.verapdf.pdfa.flavours.PDFAFlavour)
+	 * @see org.verapdf.pdfa.VeraPDFFoundry#createParser(InputStream, PDFAFlavour)
 	 */
 	@Override
 	public PDFAParser createParser(InputStream pdfStream, PDFAFlavour flavour)
@@ -127,7 +126,7 @@ public PDFAParser createParser(File file)
 	}
 
 	/**
-	 * @see org.verapdf.pdfa.VeraPDFFoundry#newMetadataFixer(org.verapdf.metadata.fixer.utils.FixerConfig)
+	 * @see VeraPDFFoundry#createMetadataFixer()
 	 */
 	@Override
 	public MetadataFixer createMetadataFixer() {
diff --git a/validation-model/src/main/java/org/verapdf/gf/model/impl/pd/GFPDExtGState.java b/validation-model/src/main/java/org/verapdf/gf/model/impl/pd/GFPDExtGState.java
index 1d3321f54..26fa2f95e 100644
--- a/validation-model/src/main/java/org/verapdf/gf/model/impl/pd/GFPDExtGState.java
+++ b/validation-model/src/main/java/org/verapdf/gf/model/impl/pd/GFPDExtGState.java
@@ -60,26 +60,6 @@ public GFPDExtGState(org.verapdf.pd.PDExtGState state) {
         super(state, EXT_G_STATE_TYPE);
     }
 
-    @Override
-    public String getTR() {
-        return getStringProperty(((org.verapdf.pd.PDExtGState) simplePDObject).getCOSTR());
-    }
-
-    @Override
-    public String getTR2() {
-        return getStringProperty(((org.verapdf.pd.PDExtGState) simplePDObject).getCOSTR2());
-    }
-
-    @Override
-    public String getSMask() {
-        return getStringProperty(((org.verapdf.pd.PDExtGState) simplePDObject).getCOSSMask());
-    }
-
-    @Override
-    public String getBM() {
-        return getStringProperty(((org.verapdf.pd.PDExtGState) simplePDObject).getCOSBM());
-    }
-
     private List<CosBM> getlinkBM() {
         COSObject BM = ((org.verapdf.pd.PDExtGState)simplePDObject).getCOSBM();
         if (BM == null || BM.empty() || BM.getType() == COSObjType.COS_NULL) {
@@ -130,17 +110,19 @@ public Double getCA() {
         return 2.0; // check is failed
     }
 
-    private static String getStringProperty(COSObject property) {
-        if (property == null
-                || property.empty()
-                || property.getType() == COSObjType.COS_NULL) {
-            return null;
-        }
+    @Override
+    public String getTR2NameValue() {
+        return simplePDObject.getNameKeyStringValue(ASAtom.TR2);
+    }
 
-        if (property.getType() == COSObjType.COS_NAME) {
-            return property.getName().getValue();
-        }
-		return property.toString();
+    @Override
+    public Boolean getcontainsTR() {
+        return simplePDObject.knownKey(ASAtom.TR);
+    }
+
+    @Override
+    public Boolean getcontainsTR2() {
+        return simplePDObject.knownKey(ASAtom.TR2);
     }
 
     @Override
@@ -153,6 +135,21 @@ public Boolean getcontainsHTO() {
         return this.simplePDObject.knownKey(ASAtom.HTO);
     }
 
+    @Override
+    public String getSMaskNameValue() {
+        return simplePDObject.getNameKeyStringValue(ASAtom.SMASK);
+    }
+
+    @Override
+    public Boolean getcontainsSMask() {
+        return simplePDObject.knownKey(ASAtom.SMASK);
+    }
+
+    @Override
+    public String getBMNameValue() {
+        return simplePDObject.getNameKeyStringValue(ASAtom.BM);
+    }
+
     @Override
     public List<? extends Object> getLinkedObjects(String link) {
         switch (link) {