/**
  * Reset the substitution table to original form
  *
  * @return $this
  */
 protected function _reset()
 {
     parent::_reset();
     $this->substitution_table->setSubstitutions(array(str_split(strrev($this->substitution_table->getPlaintextKey()))));
     return $this;
 }
 /**
  * Reset the substitution table to its original form
  *
  * @return $this
  */
 protected function _reset()
 {
     parent::_reset();
     $this->substitution_table->setSubstitutions(array(str_split(Helper::rotate($this->substitution_table->getPlaintextKey(), $this->rotation_value - 1))));
     return $this;
 }