docs: protected void checkParameters() {
          if (homeDir == null && classpath == null) {
              throw new BuildException("either home attribute or " + "classpath attributes "
                      + " must be defined for task <" + getTaskName() + "/>", getLocation());
          }
  
          if (pluginList != null) {
              // Make sure that all plugins are actually Jar files.
              String[] pluginFileList = pluginList.list();
              for (String pluginFile : pluginFileList) {
                  if (!pluginFile.endsWith(".jar")) {
                      throw new BuildException("plugin file " + pluginFile + " is not a Jar file " + "in task <" + getTaskName()
                      + "/>", getLocation());
                  }
              }
          }
  
          for (SystemProperty systemProperty : systemPropertyList) {
              if (systemProperty.getName() == null || systemProperty.getValue() == null) {
                  throw new BuildException("systemProperty elements must have name and value attributes");
              }
          }
      }