Explain EXPLAIN QUERY TREE (children 2)
 Set
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 2)
     Function if (alias value) (children 1)
      ExpressionList (children 3)
       Function greater (children 1)
        ExpressionList (children 2)
         Identifier number
         Literal UInt64_5
       Literal \'censor.net\'
       Literal \'google\'
     Identifier value
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier system.numbers
    Literal UInt64_10
