SelectWithUnionQuery (children 3)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier lhs
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier rhs
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier lhs.a
        Identifier rhs.a
 Identifier Null
 Set
