FileStructureTestCase refactoring: move logic out of setUp, allow testing by text

java/java-tests/testData/fileStructure/hierarchy/Simple.tree

@@ -1,10 +1,10 @@
 -Simple.java
  -Simple
   aaa(): void
-  bbb(): void
+  [bbb(): void]
   clone(): Object
   equals(Object): boolean
-  [fff(): void]
+  fff(): void
   finalize(): void
   getClass(): Class<?>
   hashCode(): int
@@ -13,4 +13,4 @@
   toString(): String
   wait(): void
   wait(long): void
-  wait(long, int): void
+  wait(long, int): void