code: private boolean isClientClass(String className, Set<ASMData> clientClasses)
  	{
  		for (ASMData data : clientClasses)
  		{
  			if (data.getClassName().equals(className) && data.getObjectName().equals(data.getClassName())
  					&& ((ModAnnotation.EnumHolder) data.getAnnotationInfo().get("value")).getValue().equals("CLIENT"))
  				return true;
  		}
  		return false;
  	}
docs: Checks if is the specified class has a @SideOnly(Side.CLIENT) annotation.
  
  @param className the class name
  @param clientClasses the client classes
  @return true, if is client class