Issue #3343913 by _shY, smustgrave, catch, xjm, quietone: Add comments...

      // The property path of this data object is the parent's path appended

      // by this object's name.

      $prefix = $this->parent->getPropertyPath();

      // Variables in double quotes used to leverage fast string concatenation.

      // In PHP 7+ concatenation with variable inside string is the fastest.

      // @see https://blog.blackfire.io/php-7-performance-improvements-encapsed-strings-optimization.html

      // This is being done because the code can run in the critical path.

      return $prefix !== '' ? "{$prefix}.{$this->name}" : $this->name;

    }

    // If no parent is set, this is the root of the data tree. Thus the property