This package contains the implementation of the QSS1, QSS2, and QSS3 integration methods.
In order to correctly communicate the value and the derivatives of the variable, several messages are used.
A message with type == 1 transports the value of the variable, a message with type == 2 transports the value of the first derivative, and a message with type == 3 transports the second derivative.
These messages have to be sent simultaneously.