code: public function offsetUnset($offset)
      {
          if ($offset === true) {
              $this->trueValue      = null;
              $this->trueValueIsSet = false;
          } elseif ($offset === false) {
              $this->falseValue      = null;
              $this->falseValueIsSet = false;
          } elseif (is_int($offset) || is_string($offset)) {
              unset($this->standardStore[$offset]);
          } elseif (is_float($offset)) {
              unset($this->floatStore[(string) $offset]);
          } elseif (is_object($offset)) {
              $this->objectStore->offsetUnset($offset);
          } elseif (is_array($offset)) {
              $index = array_search($offset, $this->arrayKeys, true);
  
              if ($index !== false) {
                  array_splice($this->arrayKeys, $index, 1);
                  array_splice($this->arrayValues, $index, 1);
              }
          } elseif ($offset === null) {
              $this->nullValue      = null;
              $this->nullValueIsSet = false;
          }
      }
docs: Offset to unset
  
  @link http://php.net/manual/en/arrayaccess.offsetunset.php
  
  @param mixed $offset <p>
  The offset to unset.
  </p>
  
  @return void