public String getString(String key, String defaultValue) {
        return configuration.getString(key, defaultValue);
    }
public String getString ( String key , String defaultValue ) { return configuration . getString ( key , defaultValue ) ; }
Return the String property value associated with the given key, or
{@code defaultValue} if the key cannot be resolved.

@param key          the property name to resolve
@param defaultValue the default value to return if no value is found
@return The string property