SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function replaceRegexpOne (children 1)
     ExpressionList (children 3)
      Identifier haystack
      Literal \'\'
      Identifier replacement
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test_tab
