public void setSchemaUrl(String schemaUrl) {
        if (schemaUrl != null && !schemaUrl.startsWith("http:")) {
            throw new IllegalArgumentException("schemaUrl should be a URL");
        }
        this.schemaUrl = schemaUrl;
    }
Default value is {@value #SCHEMA_URL}

@param schemaUrl
           url to the required schema
src/nu/validator/client/EmbeddedValidator.java