public ProjectImporter(final File rootFolder){
  assertNotNull("Root folder cannot be null.",rootFolder);
  assertTrue("Root folder does not exist: " + rootFolder,rootFolder.exists());
  assertTrue("Root folder must be a folder. But was a file: " + rootFolder,rootFolder.isDirectory());
  assertTrue("Root folder directory content cannot be read: " + rootFolder,rootFolder.canRead());
  assertTrue("No files were found in the directory: " + rootFolder,null != rootFolder.listFiles());
  this.rootFolder=rootFolder;
}

public ProjectImporter ( final File rootFolder ) { assertNotNull ( "Root folder cannot be null." , rootFolder ) ; assertTrue ( "Root folder does not exist: " + rootFolder , rootFolder . exists ( ) ) ; assertTrue ( "Root folder must be a folder. But was a file: " + rootFolder , rootFolder . isDirectory ( ) ) ; assertTrue ( "Root folder directory content cannot be read: " + rootFolder , rootFolder . canRead ( ) ) ; assertTrue ( "No files were found in the directory: " + rootFolder , null != rootFolder . listFiles ( ) ) ; this . rootFolder = rootFolder ; }
creates a project importer with the root folder of all projects that has to be imported for the test .
