SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Identifier arr1
    Function arrayPushFront (children 1)
     ExpressionList (children 2)
      Identifier arr1
      Identifier val2
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier array_functions
