code: @Override
    public ExprBuilderKelp buildKelp(QueryBuilderKraken builder)
    {
      ExprBuilderKelp expr = _expr.buildKelp(builder);
      ExprBuilderKelp min = _min.buildKelp(builder);
      ExprBuilderKelp max = _max.buildKelp(builder);
      
      return expr.between(min, max);
    }
docs: /*
  private BetweenExpr bindKey(QueryBuilderKraken builder,
  ExprKraken left,
  ExprKraken right)
  {
  if (_op != BinaryOp.EQ) {
  return null;
  }
  
  if (left instanceof ColumnExpr) {
  ColumnExpr leftCol = (ColumnExpr) left;
  
  if (isKey(builder.getTable(), leftCol) && right.isConstant()) {
  return new BinaryKeyExpr(leftCol, right);
  }
  else if (isHashKey(builder.getTable(), leftCol) && right.isConstant()) {
  Column keyColumn = builder.getTable().getColumn(":key_" + leftCol.getColumn().getName());
  
  return new BinaryHashKeyExpr(builder.getTable(), leftCol, keyColumn, right);
  }
  }
  
  if (right instanceof ColumnExpr) {
  ColumnExpr rightCol = (ColumnExpr) right;
  
  if (isKey(builder.getTable(), rightCol) && left.isConstant()) {
  return new BinaryKeyExpr(rightCol, left);
  }
  }
  
  return null;
  }