Using UNiagaraDataInterfaceArrayFunctionLibrary function problem

I’m trying to use functions in the UNiagaraDataInterfaceArrayFunctionLibrary class but they’re not declared as public, despite a comment in the file saying “C++ and Blueprint library for accessing array types”. Setting them to public doesn’t help, I still get compile errors when calling the function. Any pointers on how to call the functions or on how to modify the engine to make them public?