/// <summary>
        /// Initialize the sections for a working copy of a subdivision face.
        /// </summary>
        /// <param name="face">A transient face to create sections for</param>
        /// <param name="isPrimaryFace">Is the specified face the primary face?</param>
        void InitializeWorkingFace(LineSubdivisionFace face, bool isPrimaryFace)
        {
            // Create throwaway line sections (without any feature IDs, not associated with any session,
            // not in spatial index).
            FeatureFactory ff = new ThrowawayFeatureFactory(m_pop);

            ff.LineType = m_pop.Parent.EntityType;
            face.CreateSections(m_pop.Parent, ff, isPrimaryFace);

            // And calculate initial geometry
            face.CalculateGeometry(m_pop.Parent, null);
        }
        /// <summary>
        /// Initialize the sections for a working copy of a subdivision face.
        /// </summary>
        /// <param name="face">A transient face to create sections for</param>
        /// <param name="isPrimaryFace">Is the specified face the primary face?</param>
        void InitializeWorkingFace(LineSubdivisionFace face, bool isPrimaryFace)
        {
            // Create throwaway line sections (without any feature IDs, not associated with any session,
            // not in spatial index).
            FeatureFactory ff = new ThrowawayFeatureFactory(m_pop);
            ff.LineType = m_pop.Parent.EntityType;
            face.CreateSections(m_pop.Parent, ff, isPrimaryFace);

            // And calculate initial geometry
            face.CalculateGeometry(m_pop.Parent, null);
        }