public static InputStream toInputStream(CharSequence input) {
        return toInputStream(input, Charset.defaultCharset());
    }
Convert the specified CharSequence to an input stream, encoded as bytes
using the default character encoding of the platform.

@param input the CharSequence to convert
@return an input stream
@since 2.0
pay-java-common/src/main/java/com/egzosn/pay/common/util/IOUtils.java