code: @Override
  	public double getBalance(String CorpNum) throws PopbillException {
  		try {
  			return getTokenbuilder().getBalance(
  					this.getSessionToken(CorpNum, null));
  		} catch (LinkhubException le) {
  			throw new PopbillException(le);
  		}
  	}
docs: /* (non-Javadoc)
  @see com.popbill.api.BaseService#getBalance(java.lang.String)