Converts the given principal collection the byte array that will be persisted to be 'remembered' later.
<p/>
This implementation first {@link #serialize(hunt.shiro.subject.PrincipalCollection) serializes} the
principals to a byte array and then {@link #encrypt(byte[]) encrypts} that byte array.
@param principals the {@code PrincipalCollection} to convert to a byte array
@return the representative byte array to be persisted for remember me functionality.
Converts the given principal collection the byte array that will be persisted to be 'remembered' later. <p/> This implementation first {@link #serialize(hunt.shiro.subject.PrincipalCollection) serializes} the principals to a byte array and then {@link #encrypt(byte[]) encrypts} that byte array.
@param principals the {@code PrincipalCollection} to convert to a byte array @return the representative byte array to be persisted for remember me functionality.