Where does Joomla load the code in header JText::script()?

Question

Joomla

site.ru/libraries/joomla/document/html/renderer/head.php
there I see the following code

// Generate script language declarations.
    if (count(JText::script()))
    {
      $buffer .= $tab . '<script type="text/javascript">' . $lnEnd;

      if ($document->_mime != 'text/html')
      {
        $buffer .= $tab . $tab . '//<![CDATA[' . $lnEnd;
      }

      $buffer .= $tab . $tab . '(function() {' . $lnEnd;
      $buffer .= $tab . $tab . $tab . 'Joomla.JText.load(' . json_encode(JText::script()) . ');' . $lnEnd;
      $buffer .= $tab . $tab . '})();' . $lnEnd;

      if ($document->_mime != 'text/html')
      {
        $buffer .= $tab . $tab . '//]]>' . $lnEnd;
      }

      $buffer .= $tab . '</script>' . $lnEnd;
    }

Where does the JText::script() code load from? I need to fix the code, but I don't know Joomla for long.