CreateFunctionQuery udf_preprocessor (children 2)
 Identifier udf_preprocessor
 Function lambda (children 1)
  ExpressionList (children 2)
   Function tuple (children 1)
    ExpressionList (children 1)
     Identifier s
   Function concat (children 1)
    ExpressionList (children 2)
     Identifier str
     Function lower (children 1)
      ExpressionList (children 1)
       Identifier str
