docs: public final Index createAndAddExprIndexStructure(
              HsqlName name, int[] columns, Expression[] indexExprs, boolean unique, boolean migrating, boolean constraint) {
  
          Index newExprIndex = createIndexStructure(name, columns, null, null, unique, migrating, constraint, false);
          newExprIndex = newExprIndex.withExpressions(indexExprs);
          addIndex(newExprIndex);
          return newExprIndex;
      }