/// <summary>Loads all the <see cref="Vertex"/>-s from the <see cref="List{T}"/> of <see cref="CommonElement"/>-s.</summary>
        /// <param name="elements">The <see cref="List{T}"/> of <see cref="CommonElement"/>-s from which all the <see cref="Vertex"/>-s are taken.</param>
        /// <remarks>When a <see cref="CommonElement"/> is used, it is also removed from the list.</remarks>
        private void LoadVertices(List <CommonElement> elements)
        {
            for (int i = elements.Count - 1; i >= 0; i--)
            {
                CommonElement elmn = elements[i];

                if (elmn.GetStylePropertyValue("ellipse") != null)
                {
                    Vertices.Add(new Vertex(elmn.Node, elmn.StyleProperties));
                    elements.RemoveAt(i);
                }
            }
        }
        /// <summary>Loads all the <see cref="Text"/>-s from the <see cref="List{T}"/> of <see cref="CommonElement"/>-s.</summary>
        /// <param name="elements">The <see cref="List{T}"/> of <see cref="CommonElement"/>-s from which all the <see cref="Text"/>-s are taken.</param>
        /// <remarks>When a <see cref="CommonElement"/> is used, it is also removed from the list.</remarks>
        private void LoadTexts(List <CommonElement> elements)
        {
            for (int i = elements.Count - 1; i >= 0; i--)
            {
                CommonElement elmn = elements[i];

                if (elmn.GetStylePropertyValue("text") != null)
                {
                    Texts.Add(new Text(
                                  elmn.Node,
                                  elmn.StyleProperties,
                                  GetEdgeById(elmn.GetAttributeInnerText("parent"))));
                    elements.RemoveAt(i);
                    Root.RemoveChild(elmn.Node);
                }
            }
        }