code: package it.unibz.inf.ontop.model.term;
  
  import it.unibz.inf.ontop.model.type.TermType;
  import it.unibz.inf.ontop.model.type.TermTypeInference;
  
  import java.util.Optional;
  
  public interface NonNullConstant extends Constant {
  
      TermType getType();
  
      @Override
      default Optional<TermType> getOptionalType() {
          return Optional.of(getType());
      }
  
      @Override
      default boolean isNull() {
          return false;
      }
  
      @Override
      default Optional<TermTypeInference> inferType() {
          return Optional.of(TermTypeInference.declareTermType(getType()));
      }
  }
  