Gets a value that indicates whether this assertion was deserialized from XML source and can re-emit the XML data unchanged.
Assembly: System.IdentityModel (in System.IdentityModel.dll)
The default implementation preserves the source data when read using the ReadAssertion method and can re-emit the original data as long as the Id property has not changed from the time that assertion was read.
It is very important that SAML assertions with different data have different IDs. If implementing a scheme whereby an assertion "template" is loaded and certain bits of data are filled in, the Id must be changed.