Demonstration of Union components. Here four different powder samples are
placed in a can each connected to a weird sample holder and contained in
a cryostat. This unrealistic example is meant to show the syntax and the
new possibilities when using the Union components.
With the standard source only two of the samples are illuminated, yet
multiple scattering occur and events are thus taking place in the last
Example: Detector: m4pi_two_or_more_samples_I=0.0945567
Parameters in boldface are required;
the others are optional.