code: async function loadEnvConfig(nj, schema, ...vars) {
    const assignedVars = _.assign({}, ...vars);
    debug('loadEnvConfig: vars before render: ', assignedVars);
    const envVars = await templater.renderObj(nj, assignedVars);
    debug('loadEnvConfig: vars after render: ', envVars);
    if (!(isValidJsonSchema(schema, envVars))) {
      throw new Error('Environment config failed schema validation');
    }
    return envVars;
  }
docs: render and validate config with subsequent vars overriding prior vars: