diff --git a/include/Tree/tree.hpp b/include/Tree/tree.hpp
index a97a221..9f8bfb5 100644
--- a/include/Tree/tree.hpp
+++ b/include/Tree/tree.hpp
@@ -168,7 +168,21 @@ namespace Tree
     *
     * @param c - a shared_ptr to a BaseNode
     */
-    void addChild(const std::shared_ptr<Tree::BaseNode> &c) {c->setParent(shared_from_this()); children.push_back(c); }
+    void addChild(const std::shared_ptr<Tree::BaseNode> &c) {
+              if (c!=nullptr)
+              {
+                c->setParent(shared_from_this());
+                children.push_back(c);
+              }
+    }
+
+
+    /**
+    * @brief prepends a child to the node which is already a shared_ptr
+    *
+    * @param c - a shared_ptr to a BaseNode
+    */
+    void prependChild(const std::shared_ptr<Tree::BaseNode> &c) {c->setParent(shared_from_this()); children.push_front(c); }
 
     /**
     * @brief adds a container of nodes to the list of children
@@ -180,6 +194,15 @@ namespace Tree
     void addChildren(Iter begin, Iter end) { std::copy( begin, end, std::back_inserter( children ) );}
 
 
+    /**
+    * @brief prepends a container of nodes to the list of children
+    *
+    * @param begin - iterator to the beginning of the container of objects of type std::shared_ptr<Tree::BaseNode>
+    * @param end   - iterator to the end of the container of objects of type std::shared_ptr<Tree::BaseNode>
+    */
+    template <typename Iter>
+    void prependChildren(Iter begin, Iter end) { std::copy( begin, end, std::front_inserter( children ) );}
+
     /**
     * @brief finds the next node in the tree of a given type
     *
@@ -202,12 +225,25 @@ namespace Tree
     /**
     * @brief finds all nodes of a given base
     *
-    * @param base - the base type of the node as a string
+    * @param b    - the base type of the node as a string
     * @param c    - a container for holding all found nodes, has to be holding objects of type std::shared_ptr<Tree::BaseNode>
     */
-    template <typename Container>
-    void findAllBase(const std::string &base, Container &c);
+    template <class Container>
+    void findAllBase(const std::string &b, Container &c)
+    {
+      std::list<std::shared_ptr<Tree::BaseNode>>::iterator it;
 
+      if (base() == b)
+      {
+        c.push_back(shared_from_this());
+      }
+
+      for(it = children.begin(); it != children.end(); ++it)
+      {
+        (*it)->findAllBase(b,c);
+      }
+
+    }
 
     /**
     * @brief checks if the given node is a direct child of this node