code: public static void identityToString(final StringBuffer buffer, final Object object) {
          Validate.notNull(object, "Cannot get the toString of a null identity");
          buffer.append(object.getClass().getName())
                .append('@')
                .append(Integer.toHexString(System.identityHashCode(object)));
      }
docs: <p>Appends the toString that would be produced by {@code Object}
  if a class did not override toString itself. {@code null}
  will throw a NullPointerException for either of the two parameters. </p>
  
  <pre>
  ObjectUtils.identityToString(buf, "")            = buf.append("java.lang.String@1e23"
  ObjectUtils.identityToString(buf, Boolean.TRUE)  = buf.append("java.lang.Boolean@7fa"
  ObjectUtils.identityToString(buf, Boolean.TRUE)  = buf.append("java.lang.Boolean@7fa")
  </pre>
  
  @param buffer  the buffer to append to
  @param object  the object to create a toString for
  @since 2.4