public static String getSystemConfig(String keyPrefix, IConfigKey key) {
        return systemConfigs.getConfig(keyPrefix, key);
    }
public static String getSystemConfig ( String keyPrefix , IConfigKey key ) { return systemConfigs . getConfig ( keyPrefix , key ) ; }
<p>Get system config string. Config key include prefix.</p>
Example:<br>
If key.getKeyString() is "test", <br>
getSystemConfig("1.", key); will return "1.test" config value in system config file.

@param keyPrefix config key prefix
@param key       config key
@return config value string. Return null if not config in
system config file "{@value #DEFAULT_SYSTEM_CONFIG_ABSOLUTE_CLASS_PATH}" or self define system config path.
@see #setSystemConfigs(String, OneProperties)