@Override
    public void setAttributes(Map<String, String> attributes) {

        // Create independent, mutable copy of attributes
        attributes = new HashMap<>(attributes);

        // Loop through extension-specific attributes, only sending ones
        // that are non-null and non-empty to the underlying storage mechanism.
        for (String attribute : RESTRICT_CONNECTION_ATTRIBUTES) {
            String value = attributes.get(attribute);
            if (value != null && value.isEmpty())
                attributes.put(attribute, null);
        }

        super.setAttributes(attributes);

    }
Returns the original Connection object wrapped by this RestrictConnection.

@return
    The wrapped Connection object.
extensions/guacamole-auth-restrict/src/main/java/org/apache/guacamole/auth/restrict/connection/RestrictedConnection.java