Reuse Gephi's Source Code Problems

[hamtaro]

Hi everybody,

I'm a student and not good at Java. I want to write my Modularity base on Modularity source code of Gephi. So I try to use Gephi's toolkit and reuse Modularity source code of Gephi follow steps:
1. add toolkit into Netbean
2. create class "MyModularity.java" in "mypackages"
3. copy all Modularity source code to "MyModularity.java" (I haven't fixed anything, just copy and paste)

After these steps I get 2 errors:

Errors

Error 1: Missing an attribute. But I don't know what attribute I must add.
Error 2: Toolkit library not suppose function setAttribute(a,b). But Gephi's source code use this function. Can I create and add this function to use? How can I create? Where do I put it?

I need your help.
Best.
NhaNA