Explain EXPLAIN SYNTAX (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 1)
    ExpressionList (children 1)
     Function CAST (children 1)
      ExpressionList (children 2)
       Function tupleElement (children 1)
        ExpressionList (children 2)
         Function tuple (children 1)
          ExpressionList (children 3)
           Literal UInt64_3
           Literal UInt64_4
           Literal UInt64_5
         Literal UInt64_1
       Literal \'Int32\'
