Explain EXPLAIN QUERY TREE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 1)
    ExpressionList (children 2)
     Function encrypt (children 1)
      ExpressionList (children 3)
       Literal \'aes-256-ofb\'
       Subquery (children 1)
        SelectWithUnionQuery (children 1)
         ExpressionList (children 1)
          SelectQuery (children 1)
           ExpressionList (children 1)
            Literal \'qwerty\'
       Literal \'12345678901234567890123456789012\'
     Function encrypt (children 1)
      ExpressionList (children 3)
       Literal \'aes-256-ofb\'
       Subquery (children 1)
        SelectWithUnionQuery (children 1)
         ExpressionList (children 1)
          SelectQuery (children 1)
           ExpressionList (children 1)
            Literal \'asdf\'
       Literal \'12345678901234567890123456789012\'
