Explain EXPLAIN SYNTAX (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 2)
    ExpressionList (children 1)
     Function CAST (children 1)
      ExpressionList (children 2)
       Function arrayElement (children 1)
        ExpressionList (children 2)
         Function CAST (children 1)
          ExpressionList (children 2)
           Literal \'[1,2,3]\'
           Literal \'Array(UInt64)\'
         Function CAST (children 1)
          ExpressionList (children 2)
           Function arrayElement (children 1)
            ExpressionList (children 2)
             Function CAST (children 1)
              ExpressionList (children 2)
               Function array (children 1)
                ExpressionList (children 2)
                 Identifier number
                 Identifier number
               Literal \'Array(UInt8)\'
             Identifier number
           Literal \'UInt64\'
       Literal \'UInt8\'
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Function numbers (children 1)
        ExpressionList (children 1)
         Literal UInt64_3
