O quegetActivity() significar? Eu vi em algum lugar, eles escreveramMainActivity.this.startActionMode(mActionModeCallback) ao invés degetActivity(). alguém poderia explicar o que essas duas linhas significam?

  someView.setOnLongClickListener(new View.OnLongClickListener() {
        // Called when the user long-clicks on someView
        public boolean onLongClick(View view) {
            if (mActionMode != null) {
                return false;
            }

            // Start the CAB using the ActionMode.Callback defined above
            mActionMode = getActivity().startActionMode(mActionModeCallback);
            view.setSelected(true);
            return true;
        }
    });