Implementation of custom config section

i recently wrote my first custom config section. I have a collection of index files, each has a path and a savetime:

  internal class searchConfigSection : ConfigurationSection
{
    static ConfigurationProperty s_indexCollection;
    static ConfigurationPropertyCollection s_propertyCollection;
    static openSearchConfigSection()
    {
        s_indexCollection = new ConfigurationProperty("indexCollection", typeof(IndexCollection), null, ConfigurationPropertyOptions.None);
        s_propertyCollection = new ConfigurationPropertyCollection();
        s_propertyCollection.Add(s_indexCollection);
    }
    protected override ConfigurationPropertyCollection Properties
    {
        get
        {
            return s_propertyCollection;
        }
    }
    public IndexCollection IndexCollection
    {
        get { return (IndexCollection)base[s_indexCollection]; }
    }
}
internal class IndexCollection : ConfigurationElementCollection
{
    #region static fields
    static ConfigurationPropertyCollection s_properties;
    #endregion
    #region constructors
    static IndexCollection()
    {
        s_properties = new ConfigurationPropertyCollection();
    }
    public IndexCollection()
    {
    }
    #endregion
    #region override
    public override ConfigurationElementCollectionType CollectionType
    {
        get { return ConfigurationElementCollectionType.BasicMap; }
    }
    protected override string ElementName
    {
        get { return "index"; }
    }
    protected override ConfigurationPropertyCollection Properties
    {
        get { return s_properties; }
    }
    protected override ConfigurationElement CreateNewElement()
    {
        return new IndexInformation();
    }
    protected override object GetElementKey(ConfigurationElement element)
    {
        return (element as IndexInformation).Path;
    }
    #endregion
    #region indexer
    public IndexInformation this[int index]
    {
        get { return (IndexInformation)base.BaseGet(index); }
        set
        {
            if (base.BaseGet(index) != null)
            {
                base.BaseRemoveAt(index);
            }
            base.BaseAdd(index, value);
        }
    }
    #endregion
    #region modify
    public void Add(IndexInformation element)
    {
        base.BaseAdd(element);
    }

    public void Remove(string path)
    {
        base.BaseRemove(path);
    }

    public void Remove(IndexInformation element)
    {
        base.BaseRemove(GetElementKey(element));
    }

    public void Clear()
    {
        base.BaseClear();
    }

    public void RemoveAt(int index)
    {
        base.BaseRemoveAt(index);
    }

    public string GetKey(int index)
    {
        return (string)base.BaseGetKey(index);
    }
    #endregion
}
internal class IndexInformation : ConfigurationElement
{
    #region static fields
    static ConfigurationProperty s_path;
    static ConfigurationPropertyCollection s_properties;
    static ConfigurationProperty s_saveTime;
    #endregion
    #region constructor
    static IndexInformation()
    {
        s_path = new ConfigurationProperty("path", typeof(string), null, ConfigurationPropertyOptions.IsRequired);
        s_saveTime = new ConfigurationProperty("saveTime", typeof(DateTime), null, ConfigurationPropertyOptions.IsRequired);
        s_properties = new ConfigurationPropertyCollection();
        s_properties.Add(s_path);
        s_properties.Add(s_saveTime);
    }
    #endregion
    #region properties
    protected override ConfigurationPropertyCollection Properties
    {
        get { return s_properties; }

    }
    public string Path
    {
        get { return (string)base[s_path]; }
        set { base[s_path] = value; }
    }

    public DateTime SaveTime
    {
        get { return (DateTime)base[s_saveTime]; }
        set { base[s_saveTime] = value; }
    }
    #endregion
}

Here is the app.config file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<section name="searchConfig" type="Configuration.searchConfigSection,searchWindowsClient" />
</configSections>
<searchConfig>
<indexCollection>
<index path="C:\\index.xml" saveTime="" />
</indexCollecetion>
<searchConfig/>
</configuration>