code: protected Literal transformLiteralToModel(AbstractLiteral al) {
          if(al instanceof BigIntegerLiteral) {
              return new au.csiro.ontology.model.BigIntegerLiteral(((BigIntegerLiteral) al).getValue());
          } else if(al instanceof DateLiteral) {
              return new au.csiro.ontology.model.DateLiteral(((DateLiteral) al).getValue());
          } else if(al instanceof DecimalLiteral) {
              return new au.csiro.ontology.model.DecimalLiteral(((DecimalLiteral) al).getValue());
          } else if(al instanceof FloatLiteral) {
              return new au.csiro.ontology.model.FloatLiteral(((FloatLiteral) al).getValue());
          } else if(al instanceof IntegerLiteral) {
              return new au.csiro.ontology.model.IntegerLiteral(((IntegerLiteral) al).getValue());
          } else if(al instanceof StringLiteral) {
              return new au.csiro.ontology.model.StringLiteral(((StringLiteral) al).getValue());
          } else {
              throw new RuntimeException("Unexpected abstract literal "+al);
          }
      }
docs: Transforms literal from the internal representation to the canonical representation.
  
  @param al
  @return