code: public Set<AbstractConstraint<?>> getRoutingConstraints(String activity) throws PropertyException{
  		Set<String> constraintNames = getConstraintNames(activity);
  		Set<AbstractConstraint<?>> result = new HashSet<>();
  		for(String constraintName: constraintNames){
  			result.add(getConstraint(constraintName));
  		}
  		return result;
  	}
docs: Returns all routing constraints of the given activity in form of constraint-objects.
  
  @param activity The name of the activity whose routing constraints are requested.
  @return A possibly empty set of routing constraints.
  @throws ParameterException if the activity name is <code>null</code> or empty.
  @throws PropertyException if corresponding constraint-properties cannot be extracted.
  @see #getConstraintNames(String)
  @see #getConstraint(String)