public static int countIncludedChar(CharSequence charseq, char searchedChar){
		if(charseq == null){
			System.out.println("�L��Ȓl���͂��Ă�������");
		}
		
		String testedStr = charseq.toString();
		int count = 0;
		
		for(int i=0; i<testedStr.length(); i++){
			if(testedStr.charAt(i) == searchedChar){
				count++;
			}
		}
		return count;
	}