[Android] インスタンス生成の名称

Android(java)の文法についての質問です。

java
1public class SampleActivity extends Activity {
2
3    String item = "hogeImage";
4    CustomDialogFragment dialogFragment;
5
6    @Override
7    protected void onCreate(Bundle savedInstanceState) {
8        super.onCreate(savedInstanceState);
9        setContentView(R.layout.hoge_activity);
10
11        --------------処理--------------------
12
13        dialogFragment = CustomDialogFragment.newInstance(item);
14        
15        --------------処理--------------------
16
17    }
18
19    public static class CustomDialogFragment extends DialogFragment {
20
21         /** 誰？
22          *  @param imgStr
23          *  @return
24          */
25         public static CustomDialogFragment newInstance(String imgStr) {
26            CustomDialogFragment frag = new AlertDialogFragment();
27            Bundle args = new Bundle();
28            args.putString("imgStr", imgStr);
29            frag.setArguments(args);
30            return frag;
31        }
32
33        @Override
34        public Dialog onCreateDialog(Bundle savedInstanceState) {
35
36        String imgStr = getArguments().getString("imgStr");
37
38        ------------------------処理-----------------
39
40        }
41    }
42
43}