Error thrown line: 860 plugins_lib

**An error is thrown when you call:**
`$this->plugins_lib->update_all_plugin_headers();`

Error on screen:
```
A PHP Error was encountered
Severity: Notice

Message: Undefined property: Plugins::$plugins_lib

**Filename: controllers/Plugins.php**

Line Number: 18

Backtrace:

File: /home/bespokedesignservices/domains/projects.bespokedesignservices.com/public_html/smarty/application/controllers/Plugins.php
Line: 18
Function: _error_handler

File: /home/bespokedesignservices/domains/projects.bespokedesignservices.com/public_html/smarty/index.php
Line: 315
Function: require_once

An uncaught Exception was encountered
Type: Error

Message: Call to a member function update_all_plugin_headers() on null

Filename: /home/bespokedesignservices/domains/projects.bespokedesignservices.com/public_html/smarty/application/controllers/Plugins.php

Line Number: 18

Backtrace:

File: /home/bespokedesignservices/domains/projects.bespokedesignservices.com/public_html/smarty/index.php
Line: 315
Function: require_once
```
**Code from plugins_lib:**

```
/**
* Update All Plugin Headers
*
* Execute self::update_plugin_headers for each plugin found in static::$plugins
*
* @access public
* @since 0.1.0
* @return boolean
*/
public function update_all_plugin_headers()
{
if(empty(static::$plugins))
{
$this->_warn("No plugins to update headers for");

return TRUE;
}

foreach(static::$plugins as $name => $plugin)
{
$this->_debug("Updating plugin headers for {$name}");

if( ! $this->update_plugin_headers($name))
{
return FALSE;
}
}

return TRUE;
}

```