java - Binary Search Tree Remove method not working -

public class bstnode <e extends comparable<e>> {  private e value; private bstnode<e> left; public bstnode<e> right; ....   public bstnode<e>remove(e item) {     if(item.equals(this.value)){          return replacementsubtreefromchildren(this.left, this.right);      }       if (item.compareto(this.value)<0){      this.left = this.left.remove(item);     }     else{this.right = this.right.remove(item);     }     return this; }  private bstnode<e> replacementsubtreefromchildren(bstnode<e> left,       bstnode<e> right) {     if(left==null && right==null){               return null;     }     else if(left!=null && right==null){             return this.left;     }     else if(left==null && right!=null){                 return this.right;            }     else{      e getleft=this.right.getleftmostnode().getvalue();      this.value = getleft;      this.right = right.remove(getleft);       }     return this; }  /**  *  returns leftmost node in subtree formed receiver.   *    *  completion  *    *  hint: code simple. keep descending left branches,   *  until no longer possible.   *   * @returns reference leftmost node, starting receiver.      *                                            */ private bstnode<e> getleftmostnode() {    if (this.left == null) {     return this;    }    else{        return this.left.getleftmostnode();   } 

for reason method not remove tree. can me find why doing this?

i have tested , methods being accessed, suspect have pointer somewhere incorrectly cannot find where.

inst comp103 assignment 6 @ victoria university trimester