Trying to figure out which constants can be used with RowConstraints and ColumnConstraints, I found inconsistencies :

On one side, Control and Region packages are using respectively javafx.scene.control.Control.USE_COMPUTED_SIZE / javafx.scene.control.Control.USE_PREF_SIZE and javafx.scene.layout.Region.USE_COMPUTED_SIZE / javafx.scene.layout.Region.USE_PREF_SIZE.

On the other side, ConstraintsBase is using javafx.scene.layout.Region.USE_COMPUTED_SIZE / javafx.scene.layout.Region.USE_PREF_SIZE (discovered from the source code), while the javadoc is speaking about javafx.scene.layout.ConstraintsBase.CONSTRAIN_TO_PREF, and USE_COMPUTED_SIZE (no package mentioned).

To be consistent, we should have dedicated constants for ConstraintsBase :
javafx.scene.layout.ConstraintsBase.USE_COMPUTED_SIZE and
javafx.scene.layout.ConstraintsBase.USE_PREF_SIZE