code/models/EditableField.php
public function getSetting($setting)
    {
        $settings = $this->getSettings();
        if (isset($settings) && count($settings) > 0) {
            if (isset($settings[$setting])) {
                return $settings[$setting];
            }
        }

        return '';
    }
public function getSetting($setting)
    {
        $settings = $this->getSettings();
        if (isset($settings) && count($settings) > 0) {
            if (isset($settings[$setting])) {
                return $settings[$setting];
            }
        }

        return '';
    }
Return just one custom setting or empty string if it does
not exist.

@param string $setting

@return string