Triplet class

I wrote a Triplet class, it seems general purpose enough to share, so here it is:

package harsch.sandbox;

import org.apache.commons.lang.builder.CompareToBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;

/**
 * 
 * @author Tim Harsch
 * 
 * @param <L>
 * @param <M>
 * @param <R>
 */
public class Triplet<L, M, R> implements Comparable<Object> {
 private final L left;
 private final M mid;
 private final R right;

 public R getRight() {
  return right;
 } // end getter

 public M getMid() {
  return mid;
 } // end getter

 public L getLeft() {
  return left;
 } // end getter

 public Triplet(final L left, final M mid, final R right) {
  this.left = left;
  this.mid = mid;
  this.right = right;
 } // end constructor

 public static <A, B, C> Triplet<A, B, C> create(A left, B mid, C right) {
  return new Triplet<A, B, C>(left, mid, right);
 } // end factory method

 @Override
 public final boolean equals(Object o) {
  if (!(o instanceof Triplet<?, ?, ?>))
   return false;

  final Triplet<?, ?, ?> other = (Triplet<?, ?, ?>) o;
  return equal(getLeft(), other.getLeft())
    && equal(getMid(), other.getMid())
    && equal(getRight(), other.getRight());
 } // end method

 public static final boolean equal(Object o1, Object o2) {
  if (o1 == null) {
   return o2 == null;
  }
  return o1.equals(o2);
 } // end method

 @Override
 public int hashCode() {
  return new HashCodeBuilder(17, 13).append(this.left).append(this.mid)
    .append(this.right).toHashCode();
 } // end method

 @Override
 public int compareTo(Object o) {
  Triplet<?, ?, ?> other = (Triplet<?, ?, ?>) o;
  return new CompareToBuilder().append(this.left, other.left).append(
    this.mid, other.mid).append(this.right, other.right)
    .toComparison();
 } // end method

 @Override
 public String toString() {
  StringBuilder sb = new StringBuilder();
  sb.append('<');
  if (left == null) {
   sb.append("null");
  } else {
   sb.append(left.toString());
  } // end if
  sb.append(',');
  if (mid == null) {
   sb.append("null");
  } else {
   sb.append(mid.toString());
  } // end if
  sb.append(',');
  if (right == null) {
   sb.append("null");
  } else {
   sb.append(right.toString());
  } // end if
  sb.append('>');
  return sb.toString();
 } // end method
} // end class