diff --git a/CloudObjects/SDK/NodeReader.php b/CloudObjects/SDK/NodeReader.php
index a5201f2..a4ac37d 100644
--- a/CloudObjects/SDK/NodeReader.php
+++ b/CloudObjects/SDK/NodeReader.php
@@ -38,7 +38,7 @@ class NodeReader {
      * @param string|object $type The type to check for.
      * @return boolean
      */
-    public function hasType(?Node $node = null, $type) {
+    public function hasType(?Node $node, $type) {
         if (!isset($node))
             return false;
         $type = $this->expand($type);
@@ -60,7 +60,7 @@ class NodeReader {
         return false;
     }
 
-    private function getFirstValue(?Node $node = null, $property, $default = null) {
+    private function getFirstValue(?Node $node, $property, $default = null) {
         if (!isset($node))
             return $default;
         $valueFromNode = $node->getProperty($this->expand($property));
@@ -82,7 +82,7 @@ class NodeReader {
      * @param $default The default that is returned if no value for the property exists on the node.
      * @return string|null
      */
-    public function getFirstValueString(?Node $node = null, $property, $default = null) {
+    public function getFirstValueString(?Node $node, $property, $default = null) {
         $valueFromNode = $this->getFirstValue($node, $property, $default);
         if ($valueFromNode == $default)
             return $default;
@@ -103,7 +103,7 @@ class NodeReader {
      * @param $default The default that is returned if no value for the property exists on the node.
      * @return bool|null
      */
-    public function getFirstValueBool(?Node $node = null, $property, $default = null) {
+    public function getFirstValueBool(?Node $node, $property, $default = null) {
         return (in_array(
             $this->getFirstValueString($node, $property, $default),
             [ '1', 'true' ]
@@ -120,7 +120,7 @@ class NodeReader {
      * @param $default The default that is returned if no value for the property exists on the node.
      * @return int|null
      */
-    public function getFirstValueInt(?Node $node = null, $property, $default = null) {
+    public function getFirstValueInt(?Node $node, $property, $default = null) {
         $value = $this->getFirstValueString($node, $property);
         if (is_numeric($value))
             return (int)($value);
@@ -138,7 +138,7 @@ class NodeReader {
      * @param $default The default that is returned if no value for the property exists on the node.
      * @return float|null
      */
-    public function getFirstValueFloat(?Node $node = null, $property, $default = null) {
+    public function getFirstValueFloat(?Node $node, $property, $default = null) {
         $value = $this->getFirstValueString($node, $property);
         if (is_numeric($value))
             return (float)($value);
@@ -156,7 +156,7 @@ class NodeReader {
      * @param $default The default that is returned if no value for the property exists on the node.
      * @return string|null
      */
-    public function getFirstValueIRI(?Node $node = null, $property, ?IRI $default = null) {
+    public function getFirstValueIRI(?Node $node, $property, ?IRI $default = null) {
         $valueFromNode = $this->getFirstValue($node, $property, $default);
         if ($valueFromNode == $default)
             return $default;
@@ -177,7 +177,7 @@ class NodeReader {
      * @param $default The default that is returned if no value for the property exists on the node.
      * @return string|null
      */
-    public function getFirstValueNode(?Node $node = null, $property, ?Node $default = null) {
+    public function getFirstValueNode(?Node $node, $property, ?Node $default = null) {
         $valueFromNode = $this->getFirstValue($node, $property, $default);
         if ($valueFromNode == $default)
             return $default;
@@ -196,7 +196,7 @@ class NodeReader {
      * @param string|object $value The expected value.
      * @return boolean
      */
-    public function hasPropertyValue(?Node $node = null, $property, $value) {
+    public function hasPropertyValue(?Node $node, $property, $value) {
         if (!isset($node))
             return false;
         $valuesFromNode = $node->getProperty($this->expand($property));
@@ -225,14 +225,14 @@ class NodeReader {
      * @param string|object $property The property to read.
      * @return boolean
      */
-    public function hasProperty(?Node $node = null, $property) {
+    public function hasProperty(?Node $node, $property) {
         if (!isset($node))
             return false;
         
         return ($node->getProperty($this->expand($property)) != null);
     }
 
-    private function getAllValues(?Node $node = null, $property) {
+    private function getAllValues(?Node $node, $property) {
         if (!isset($node))
             return [];
 
@@ -248,7 +248,7 @@ class NodeReader {
      * Get the language-tagged-string for the property in the specified language.
      * If no value is found for the specified language, the default is returned.
      */
-    public function getLocalizedString(?Node $node = null, $property, $language, $default = null) {
+    public function getLocalizedString(?Node $node, $property, $language, $default = null) {
         $values = $this->getAllValues($node, $property);
         foreach ($values as $v) {
             if (is_a($v, 'ML\JsonLD\LanguageTaggedString') && $v->getLanguage() == $language)
@@ -265,7 +265,7 @@ class NodeReader {
      * @param string|object $property The property to read.
      * @return array<string>
      */
-    public function getAllValuesString(?Node $node = null, $property) {
+    public function getAllValuesString(?Node $node, $property) {
         $allValues = $this->getAllValues($node, $property);
         $output = [];
         foreach ($allValues as $a)
@@ -284,7 +284,7 @@ class NodeReader {
      * @param string|object $property The property to read.
      * @return array<bool>
      */
-    public function getAllValuesBool(?Node $node = null, $property) {
+    public function getAllValuesBool(?Node $node, $property) {
         $allValues = $this->getAllValuesString($node, $property);
         $output = [];
         foreach ($allValues as $a)
@@ -300,7 +300,7 @@ class NodeReader {
      * @param string|object $property The property to read.
      * @return array<bool>
      */
-    public function getAllValuesInt(?Node $node = null, $property) {
+    public function getAllValuesInt(?Node $node, $property) {
         $allValues = $this->getAllValuesString($node, $property);
         $output = [];
         foreach ($allValues as $a)
@@ -316,7 +316,7 @@ class NodeReader {
      * @param string|object $property The property to read.
      * @return array<bool>
      */
-    public function getAllValuesFloat(?Node $node = null, $property) {
+    public function getAllValuesFloat(?Node $node, $property) {
         $allValues = $this->getAllValuesString($node, $property);
         $output = [];
         foreach ($allValues as $a)
@@ -333,7 +333,7 @@ class NodeReader {
      * @param string|object $property The property to read.
      * @return array<IRI>
      */
-    public function getAllValuesIRI(?Node $node = null, $property) {
+    public function getAllValuesIRI(?Node $node, $property) {
         $allValues = $this->getAllValues($node, $property);
         $output = [];
         foreach ($allValues as $a)
@@ -351,7 +351,7 @@ class NodeReader {
      * @param string|object $property The property to read.
      * @return array<Node>
      */
-    public function getAllValuesNode(?Node $node = null, $property) {
+    public function getAllValuesNode(?Node $node, $property) {
         $allValues = $this->getAllValues($node, $property);
         $output = [];
         foreach ($allValues as $a)