Connection with Arduino IDE

[ujur007]

I am using Easymesh in Arduino IDE to program ESP8266.
I get error in using some functions provided. I have some questions.

when I Download and include easyMesh.h in my program, what happens to the parameters of the function, functions which are not defined in easyMesh.h but in other files like easyMesh.cpp in the same folder? Will the compiler automatically search those things?

Some functions like the one below has 2 different names, which one should I use?

###void easyMesh::setReceiveCallback( &receivedCallback ) Set a callback routine for any messages that are addressed to this node. The callback routine has the following structure…

void receivedCallback( uint32_t from, String &msg )

I get error in the following line
mesh.setReceiveCallback( uint32_t ID, String &msg); //error is here