Class org.sbml.jsbml.UnitDefinition

Added Methods
Unit createInvalidUnit()	Creates a new Unit instance with the Unit.Kind.INVALID kind and adds it to this UnitDefinition.
boolean isListOfUnitsEmpty()	Returns {@code true} if the listOfUnits is empty.
boolean isVariantOfDimensionless()	Tests if a given unit definition is a variant of the predefined unit identifier 'dimensionless'.