code: protected final void checkRequiredParameter(Object value, String name) {
      Preconditions.checkArgument(
          abstractGoogleClient.getSuppressRequiredParameterChecks() || value != null,
          "Required parameter %s must be specified", name);
    }
docs: Ensures that the specified required parameter is not null or
  {@link AbstractGoogleClient#getSuppressRequiredParameterChecks()} is true.
  
  @param value the value of the required parameter
  @param name the name of the required parameter
  @throws IllegalArgumentException if the specified required parameter is null and
  {@link AbstractGoogleClient#getSuppressRequiredParameterChecks()} is false
  @since 1.14