i.e., the ECL restart files are not necessarily updated after each
report step, but only each N-th (where N is the number specified by
the EclOutputInterval parameter). if this value is set to something
smaller than zero, the value which is computed by the EclipseState
object is used.
IMO the term "vanguard" expresses better what these classes are
supposed to do: level the ground for the cavalry. Normally this simply
means to create and distribute a grid object, but it can become quite
a bit more complicated, as exemplified by the vanguard classes of
ebos..