System.Security.Util.StringExpressionSet.Intersect C# (CSharp) Method

        public StringExpressionSet Intersect( StringExpressionSet ses )
        {
            // If either set is empty, the intersection is empty
            
            if (this.IsEmpty() || ses == null || ses.IsEmpty())
                return CreateNewEmpty();
            
            CheckList();
            ses.CheckList();
            
            // Do the intersection for real
            
            StringExpressionSet intersectSet = CreateNewEmpty();
            
            for (int this_index = 0; this_index < this.m_list.Count; ++this_index)
            {
                for (int ses_index = 0; ses_index < ses.m_list.Count; ++ses_index)
                {
                    if (StringSubsetString( (String)this.m_list[this_index], (String)ses.m_list[ses_index], m_ignoreCase ))
                    {
                        if (intersectSet.m_list == null)
                        {
                            intersectSet.m_list = new ArrayList();
                        }
                        intersectSet.AddSingleExpressionNoDuplicates( (String)this.m_list[this_index] );
                    }
                    else if (StringSubsetString( (String)ses.m_list[ses_index], (String)this.m_list[this_index], m_ignoreCase ))
                    {
                        if (intersectSet.m_list == null)
                        {
                            intersectSet.m_list = new ArrayList();
                        }
                        intersectSet.AddSingleExpressionNoDuplicates( (String)ses.m_list[ses_index] );
                    }
                }
            }
            
            intersectSet.GenerateString();
            
            return intersectSet;
        }