Solution: Kara, the tunnel seeker II

Kara walks straight ahead until there is a tree to his left and right. Then he continues until there no tree either to his left or right.

public void myProgram() {
  while (! (kara.treeLeft() && kara.treeRight())) {
    kara.move();
  }

  while (kara.treeLeft() && kara.treeRight()) {
    kara.move();
  }
}