code: public function push($type, $value, $reference = null)
      {
          $this->stack[$this->count++] = [
              'type' => $type,
              'value' => $value,
              'reference' => $reference,
          ];
          if ($type == 'Function') {
              $localeFunction = Calculation::localeFunc($value);
              if ($localeFunction != $value) {
                  $this->stack[($this->count - 1)]['localeValue'] = $localeFunction;
              }
          }
      }
docs: Push a new entry onto the stack.
  
  @param mixed $type
  @param mixed $value
  @param mixed $reference