#vulnerable code 
                             public boolean valueAsBoolean() throws IOException {
		if (BOOLEAN == valueType) {
			return _booleanValue;
		}
		if (STRING == valueType)
			return "".equals(_stringValue) ? null : Boolean.valueOf(_stringValue);
		if (NULL == valueType) return false;
		throw new IllegalStateException("Readen value is not of type boolean");
	} 
                            #location 6 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             public boolean valueAsBoolean() throws IOException {
		if (BOOLEAN == valueType) {
			return _booleanValue;
		}
		if (STRING == valueType)
			return Boolean.parseBoolean(_stringValue);
		if (NULL == valueType) return false;
		throw new IllegalStateException("Readen value is not of type boolean");
	}