src/Module/ModuleManager.php
public function isModified($module)
    {
        $module = Inflector::camelize($module);

        if (!isset($this->loadedModules[$module])) {
            return -1;
        }

        return $this->loadedModules[$module]['modified'];
    }
public function isModified($module)
    {
        $module = Inflector::camelize($module);

        if (!isset($this->loadedModules[$module])) {
            return -1;
        }

        return $this->loadedModules[$module]['modified'];
    }
Returns if a module has been modified or -1 if we do not have it

@param string $module The module to check.

@return bool|int