Study the following method carefully which can be related to a certain class, decide what does it do?

public void Unknown(E item)

{

Node node = new Node(item);

Node parent=null, current;

char d;

if(root == null)

root = node;

else

{

current = root;

while(current != null)

{

parent = current;

if (current.data < item)

{ current = current.right;

d=r; }

else

{ current = current.left;

d=l;

}

}

if(d==l)

parent.left = node;

else

parent.right = node;

}

}