code: public void setWarning(String value) {
      if ("default".equalsIgnoreCase(value)) {
        this.warningLevel = WarningLevel.DEFAULT;
      } else if ("quiet".equalsIgnoreCase(value)) {
        this.warningLevel = WarningLevel.QUIET;
      } else if ("verbose".equalsIgnoreCase(value)) {
        this.warningLevel = WarningLevel.VERBOSE;
      } else {
        throw new BuildException(
            "Unrecognized 'warning' option value (" + value + ")");
      }
    }
docs: Set the warning level.
  @param value The warning level by string name. (default, quiet, verbose).