/// <summary>
/// Adds the given <see cref="Scheme"/> instance to the extent set. If
/// the <see cref="Scheme"/> has the same URI as an existing entry then
/// it will replace the old definition.
/// </summary>
/// <param name="scheme">The <see cref="Scheme"/> instance to be added.</param>
/// <returns>A reference to the old <see cref="Scheme"/> object replaced
/// by this action, <c>null</c> otherwise.</returns>
public Scheme Add(Scheme scheme)
{
Scheme resultA = schemes.ContainsKey (scheme.Uri) ? schemes [scheme.Uri] : null;
Scheme resultB = null;
if (scheme.CanonicalUri != null) {
resultB = schemes.ContainsKey (scheme.CanonicalUri) ? schemes [scheme.CanonicalUri] : null;
schemes [scheme.CanonicalUri] = scheme;
}
schemes [scheme.Uri] = scheme;
return ((resultA != null) ? resultA : resultB);
}
/// <summary>
/// Removes the indicated <see cref="Scheme"/> instance from the extent
/// set.
/// </summary>
/// <param name="scheme">The <see cref="Scheme"/> to be removed.</param>
/// <returns>A reference to the <see cref="Scheme"/> if it was in the
/// extent set, <c>null</c> if it was not.</returns>
public Scheme Remove(Scheme scheme)
{
Scheme resultA = null;
Scheme resultB = null;
if (schemes.ContainsKey (scheme.Uri))
schemes.Remove ((resultA = scheme).Uri);
if (scheme.CanonicalUri != null)
if (schemes.ContainsKey (scheme.CanonicalUri))
schemes.Remove ((resultB = scheme).CanonicalUri);
return ((resultA != null) ? resultA : resultB);
}