stylesheet: I_gdome_xslt.processed_stylesheet ->
unit
+(** set error callback, that is a function invoked each time an error message is
+generated. If None is passed, libxslt default error callback is used *)
+val setErrorCallback: (string -> unit) option -> unit
+
+(** set debug callback, that is a function invoked each time a debugging message
+is generated. If None is passed, libxslt default error callback is used *)
+val setDebugCallback: (string -> unit) option -> unit
+